X(1835) as Proton-Antiproton Bound State in Skyrme Model
  We present a review to the recent works related to interpreting the exotic particle X(1835) reported by BES as a $N\bar{N}$-baryonium in the Skyrme model.   There are two evidences that support this interpretation: 1) There exist a classical $N\bar{N}$-Skyrmion solution with about $\sim 10$MeV binding energies in the model; 2) The decay of this Skymion-baryonium is caused by annihilation of $p-\bar{p}$ inside X(1835) through the quantum tunneling effect, and hence the most favorable decay channels are $X\to \eta 4\pi$ or $X\to \eta' 2\pi$. These lead to reasonable interpreting the data of BES, and especially to useful prediction on the decay mode of X(1835) for the experiment. 
Mu-Lin Yan