Abstract: The interpolation experiments and statistics calculations of missing annual precipitation have been done using mean Generating Function(MGF)and one-dimensional Chebyshev polynomials (CP).The results have shown that MGF for fitting and interpo-lationaccuracy of missing annual precipitation are usually higher than CP,especially missing data with continuous many years and at beginning of series. In the case of using same method,accuracy of fitting for onlyone year missing is higher than that of many years. But there are not big difference between fitting results while 4-5a missing data in different location of data series. However accuracy of fitting forseveral parts missing at the same time is lower than that of only one part missing.