Climatic precipitations especially Rainfall are of great importance for many hydrological plans and analysis. Unfortunately, in many cases, the data of rain gauge stations have insufficient rainfall and also unsuitable spatial distribution. Furthermore, the precise estimation of rainfall spatial dispensation need very compact network with much expense of installation and performance. Furthermore, the precise estimation of rainfall spatial dispensation require very compact network accompined with much expense of installation and performance. Regarding the current condition, precipitation estimation in non- gaged points is one of the great goals for water resources management and it is also so important in managing these resources. Therefore, the current survey focuses on generating rainfall data for Zayandehroud dam basin using deterministic methods including thiessen (THI) and inverse distance weighting (IDW) and also geostatistical methods consist of ordinary kriging (ORK) and universal kriging (UNK) in daily time step for a period of 20 years. In order to validate the generated data, the measured data of three stations inside basin named Chelgerd, Chadegan and Mirabad being selected through cluster analysis process, were employed. The interpolatin process through Different station number including 27, 15, 10 and 5 stations has been carried out to make data for each of three control stations using jack knife methods. The results of generated data were evaluated in both daily and seasonal time step using four comparizonal parameter including correlation coefficient, root mean square error, mean absolutre error and mean biase error. According to the outputs, the experimental Guassian model has been selected as the best fitted model to semivariogram. The results of interpolation using different methods for Chadegan station indicated the ordinary kriging is the best method in interpolation via 27 stations. As the number of stations (station’s network) is decreased, the performance of geostatistical methods are decreased sabsequently and the function of deterministic methods is prodominant. The universal kriging (UNK) had better results for Mirabad station in interpolation via different stations network. Being away from other stations, the condition of Chelgerd was different from other tow stations. The Thiessen polygon was dominant in interpolation via 5 stations for all three control stations. The best method for seasonal generated data was variable but generally when the number of station are so many (27 stations) and also the amount of rainfall is so high (winter season), the ordinary kriging is prevalent. In addition, deterministic methods like thiessen will make more precise results as the station network disperses (5 stations) and also when there is less precipitation rate (summer season). It is worth to note that sometimes rising in number of station will not result in more accurate data. In this study, the generated data using 15 stations were not better than 10 stations. In interpolation via 15 stations, there was a weak correlation rate among stations and this is because of the distribution position of stations in the basin. Sometimes it’s possible to have better interpolation resulta in less station number but better distribution position. The most appropriate method of interpolation is up to optimum number of station and their diension through basin and also climatic condition of area. The results of this survey are capable to use in many researches especially hydrologic model. Key words : Interpolation, Kriging, Zayandehroud dam basin, Geostatistic, Semivariogram and Mapping.