scalar field has a nearly flat region, the value of whose energy density equals to that of cosmological constant observed, and a minimum with negative energy density. When the field is in the nearly flat region of potential, we can have a period of dark energy, and then it rolls down towards its minimum with negative potential energy den- sity, which leads to the collapse of universe, the contrac- tion with w ≃ 0 can be obtained by the oscillation of field around its minimum. In this case, it is obvious that the evolution that the period of dark energy domination precedes the contraction with w ≃ 0 can be obtained. In general, the period of dark energy will help to dilute the matter and radiation in i cycle, which assures that in j cycle the energy density of matter and radiation from i cycle can not exceed that of field till the enough efold- ing number is obtained. In addition, the anisotropy and some baneful leftovers, which are menaces for cycling, e.g. discussions in [3], can be also diluted during this pe- riod of dark energy. Thus it is required that this period should be enough long. i.e. the corresponding potential should be enough flat. In different cycle of cyclic universe, the universe can be in different minima of a given potential in field space, or landscape 8 [5], in which these minima have negative potential energy density. Here, the generality is actu- ally straight. Thus in principle it can be argued that in a cyclic multiverse scenario, generally each of multiverse will have different minima and thus evolutions. However, in this case, the requirement for an enough period of ac- celerated expansion in i cycle actually corresponds to a fine tunning for the initial condition of j cycle. Thus though in a cyclic universe driven by a given landscape, the number of universes having an enough long period of dark energy domination might be quite small, such uni- verses can certainly exist, which is significant not only for assuring the continuance of cycle, but also for the emergence of observable universe in which we might live. In general, in a string landscape both positive and neg- ative minima exist. However, unless all minima in the landscape are negative, the cycle of universe will not con- tinue eternally, since if the universe enters into a positive minimum, it will stop cycling, and expand for ever, as illustrated earlier in [12]. In cyclic universe [2], the effect of the increase of met- ric perturbation on global universe has been discussed in [43]. However, in this model it requires that on su- per horizon scale the increasing mode of metric per- turbation is inherited by the constant mode of curva- ture perturbation in leading order. Whether the cor- responding inheriting can occur remains controversial [44],[45],[46],[47],[48],[49],[50],[51]. However, if this dose not occur, the same mode is decayed during the expan- 8 In the low energy limit, the string landscape can be visualised as an effective potential in a given field space with multiple dimen- sions. In conclusion, in a cyclic universe, since the metric perturbation on super horizon scale is amplified cycle by cycle, after each cycle the universe will be inevitably sep- arated into many parts independent of one another, each of which corresponds to a new universe and evolves up to succedent cycle, and then is separated again. This mech- anism brings us a scenario of cyclic multiverse, in which the number of universes increases cycle by cycle. How- ever, in general, the amplitude of perturbation modes in previous cycle can be preserved and amplified in current cycle, which is generally larger than that induced by the quantum fluctuation of background field in current cycle. This baffles the possibility that this scenario is regarded as the origin of observable universe. We, in this paper, have provided a viable design of a cyclic multiverse, in which the observable universe can emerge naturally. The significance of a long period of dark energy before the In cyclic inflation [11],[12], the scale factor in consec- utive cycles increases by a constant factor. This, after some cycles, can give a net exponential growth of the scale factor, and thus can imitate inflation. Whether there can be a scale invariant spectrum in this model remains an open issue. However, combining it with the result obtained here, we might argue that a multiverse will come into being after cyclic inflation, some of which might have a subsequent period of slow roll inflation and thus correspond to our observable universe. In a class of oscillating universe, in which the bounce is implemented by quintom matter [8],[20],[53], the cyclic multiverse scenario might be naturally applied, since a period of dark energy can be congenitally included in this model. This study can be in order. In [54], a scenario that many small contracting universes can be spawned at the end of each cycle has been proposed, which is imple- mented by appealing to the brane world cosmology and the phantom dark energy. In the design given here, these additional appeals are needless, the mechanism resulting in the multiverse is the natural increase of perturbation on super horizon scale. The role of a period of dark en- ergy for cycling was also discussed in [55], in which the appearance of new universe is obtained by the wormholes leaded by the accretion of phantom dark energy [56]. sion of each cycle, thus even if it is increased during the contraction, the net result is still decayed in each cycle, since in each cycle the amount of the expansion of the universe is generally larger than that of the con- traction. Here, however, the increasing mode of metric perturbation is inherited by the constant mode of cur- vature perturbation in k 2 order, which certainly occurs for the bounce connecting the contracting and expanding phases, e.g. [29, 52] for theoretical and numerical studies. The metric perturbation after the bounce will be dom- inated by the same constant mode as that of curvature perturbation. Thus the net amplitude of metric pertur- bation is increased in each cycle. We has argued this effect will potentially lead to a cyclic multiverse [14]. In this paper, the problems baffling this multiverse scenario is discussed, and the possible solution is designed. 5