Due to the increasing rate of population, developing the agricultural and industrial activates, sever need for water, wrong usage (of water), on the one hand, and the occurrence of the drought on the other hand, it is necessary in the present situation to understand the water potentials of every region in order to make decision about the protection and utilization of water resources. Because of the great significance of the Karst Water Resources, it is very important to recognize and study the effective factors in the amount of their discharge. In this research 27, 24 and 23 climatic variable were in turn obtained from the meteorology statistic of the synoptic station of Khorramabad in a large scale and using different regression methods, the role of the most important one about the variable of annual, seasonal and monthly discharge amount of the four Karstic Water Resources of Khorramabad, were studied and analyzed with regard to the statistic indicators such as the R-sq indicator. Through the method of the best subsets, 3 to 5 parameters were used in the regression equation of every water resource, and after testing the needed theories, the practicality of these models in the annual scale for the water resource of Motahary, Golestan, Kio, and Gerdab Sangy whit the R-sq of in turn 73.1%, 0.55, 0.82.5 was approved. Overall findings showed that multiple regression equations obtained to predict the discharge of Karstic Springs Khorramabad, precipitation variables of Monthly periods, seasonally and annual have weaker roles than the temperature variables. Lowest temperatures were recognized as an effective variable in the estimated values of discharge, among the variables of temperature.