The size distribution and distribution function of ice crystals within mixed and cold cloud in Inner-Mongolia, Shan Xi, and Xin Jiang region were given. The size distribution of ice crystals may be classified to mono-decreasing type and non-mono-decreasing type. The size distribution function may be fitted with exponential for-mulaN (D)=N0exp (-XD). Samples of correlation significance level α<0.01 hold 99% or more of total samples. Within cold cloud distribution parameters N0 and λ increase with cloud temperature decreases. While at T<-10℃ layer, N0and λ increase apparently. We proposed the correlation relation between the N0and λ in the form of N=σλβ.