: Drought is a natural creeper phenomenon which is seen more in dry and semi dry regions. Central, eastern and southern parts of Iran with dry and semi-dry climate are accounted among these regions.So investigation, recognition, and analyzing drought in Iran country are very necessary in specially desert province of Yazd . In this research, 5 percent of normal Precipitation Index (I),Deciles of Precipitation(DPI),Rainfall Anomaly Index (RAI), Bahlme Mooley Drought Index (BMDI) and standardized Precipitation Index (SPI) have been used in order to investigate drought in Yazd synoptic station and 31 non synoptic stations all around this province. For this purpose, the present statistical faults were renovated via correlation between the stations, after raining data collection from the considered stations. Then, calculation of I, DPI, RAI indexes were done in monthly and annual scales , BMDI index was calculated in during 12,9 and 7 month evaluation period and SPI index was calculated in 3,6-9 and 12 month time scales. Situation of drought was determined based on the obtained values from calculation of each indexes according to tables related to considered indexes in the different Then each index were compared to each other, considering to drought given situation for each stations in the considered time scales and difference and similarity of each index with other 4 indexes were calculated and investigated, also after determination of drought situation in each stations, given percentage of drought different situations via each percent of normal Precipitation Index (I), Rainfall Anomaly Index (RAI) and Deciles of Precipitation (DPI) was determined in annual scales, Bahlme Mooley Drought Index in during 9 12 month assessment cycles(BMDI) and standardized Precipitation Index in 12 month time scale (SPI 12 ) in 33 under studying stations. After passing the above mentioned stages it was defined that there is the most percentage value of similarity between two indexes RAI DPI, as both indexes indicated similar situation of hard drought in the stations and these two indexes are consisted on the most efficiency to investigate aerology drought. But considering to this that static indexes are faced to accounting problem in monthly scales and in stations located in drought regions, so it is recommended to use SPI in 6 12 month time scales amMDI in during 7 9 month assessment cycles dynamic indexes which their similarity percent is acceptable
