by that the average energy density of W − matter (mirror matter) is equal to that of F − matter (ordinary matter). According to the present model, there are three sorts of dark matter which are v − W − baryon matter (4 / 27) and unknown v − F − matterv (9 . 5 / 27) and v − W − matter (9 . 5 / 27) . Given v − F − bayon matter (4 / 27) can cluster to form the visible galaxies. V − W − bayon matter can cluster to form dark celestial bodies and dark galaxies. Unknown v − F − matterv and v − W − matter cannot cluster to form any celestial body, loosely distribute in space, are equivalent to cold matter, and their compositions are unknown. The number in a bracket is the ratio of the density of a sort of matter to total density of v − matter . The decisive predict is that there are dark celestial bodies and dark galaxies. The energy of F − matter can transform into the energy of W − matter by such a process in which the reaction energy is high enough. I am very grateful to professor Zhao Zhan-yue and professor Wu Zhao-yan for their helpful discussions and best support. Acknowledgement [1] Z. Berezhiani, D. Comelli and F. L. Villante, Phys. Lett. B 503 (2001) 362-375. [2] Y. Ignatiev and R. R. Volkas, Phys. Rev. D 68 (2003) 023518. [3] S-H. Chen, ‘Quantum Field Theory Without Divergence A’ hep-th/0203220, ‘Quantum Field Theory :New Research’, O. Kovras Editor, Nova Science Publishers, Inc. (2005), p103-170. ‘Significance of Negative Energy State in Quantum Field Theory A’ hep-th/0203230. [4] S-H. Chen, ‘A Possible Candidate for Dark Matter’, hep-th/0103234; ‘Progress in Dark Matter Research’ Editor: J. Val Blain, pp.65-72. 2005 Nova Science Publishers, Inc. [5] S-H. Chen, ‘A Possible Universal Model without Singularity and its Explanation for Evolution of the Universe’, hep-ph/0611283; ‘Discussion of a Possible Universal Model without Singularity’, arXiv. 0908.1495. [7] S-H. Chen, ‘ SU (5) Grand Unified Model and Dark Matter’, arXiv. 0912.2427. [6] R.R.Caldwell, Phys. World 17 , 37 (2004); T.padmanabhan, Phys. Rep. 380 . 325 (2003); P.J.E. Peebles and B. Ratra; Rev. Mod. Phys. 75 ,559 (2003). 10