It is considered that optical fiber channels modeled by the stochastic nonlinear Schrodinger equation and operating at zero dispersion. The statistic characteristic of optical fiber channel with noise was analyzed. In order to find the capacity of the dispersionless optical fiber channel, one first needs to statistically model the communication channel. The Schrodinger equation added noise was modeled. The stochastic differential equations(SDEs) in polar coordinates were built by using It? formula. The Fokker-Planck equation of SDEs were presented and the probability density function(PDF) was given. As a result of the Kerr nonlinearity and its interaction with amplified spontaneous emission noise, the amplitude and phase channels correlate with each other and the statistics of the received signal are non-Gaussian.