Tody, drought is a danger to human well-being and life, and its lack of control reduces groundwater and surface water. Considering that Karkhe and karoon watershed is one of the most important areas of the country in terms of water, energy and agricultural production, it is necessary to identify the effective factors in order to avoid water shortages. The purpose of this study was to analyze the multivariate hydrologic indices in 29 selected stations from Karkhe and karoon rivers, providing several hydrological indicators and their relationship with the physiognomy of the basin. In the present study, 29 stations with good hydrometric stations were selected and distributed in the region. Then, they introduced 35 hydrologic indicators, which are divided into 5 groups that characterize the defferent characteristics of the flow regime, including Amplitud, Duration, Frequency, Timing and Variability.The methodology is used to calculate and Principal Component Analysis (PCA) of the hydrological indicators for the karoon areas, which includes 14 stations and Karkhe containing 15 stations, which after the Principal Component Analysis the most important indicators identified in the Karkhe basin, the most significant indicators A2,A8,A11,A12,D6,V2,FandTrespectively (Mean of the daily mean flow values for the entire flow record, Mean of the minimums of all June flow values over the entire record, Mean of the minimums of all September flow values over the entire record, Mean of the minimums of all October flow values over the entire record, Average of annual 90-day minimum flows, Coefficient of variation of annual 7-day minimum flow, Average number of flow events with flows below a threshold equal to the 25th percentile value for the entire flow record and Mean Julian date of annual minimum) and in the karoon basin, the most significant indicators A2,A4, D3,D5,V1,F and Trespectively (Median of the daily mean flow values for the entire flow record, Mean of the minimums of all February flow values over the entire record, 90-day minimum, Average of annual 30-day minimum flows, Coefficient of variation of the annual minimum monthly discharges, Average number of flow events with flows below a threshold equal to the 25th percentile value for the entire flow record and Mean Julian date of annual minimum). The results showed that in both watersheds, the indices of the Amplitude group (A)produced the greatest difference between the hydrometric stations, and the Duration and Variability of the flow generated the most similarities between the hydrometric stations. Also, hydrometric station of Karkhe and karoon basins, 5 factors area, length of waterway, rive net slope, average gradient and gravelian coefficient as important factors have the greatest impact on the minimum flow in these basins. Key words: Principal Component Analysis, Karkhe river basin, Karoon river basin, multivariable regression, hydrologic index