Abstarct: Regarding the importance of hard rocks in storing water resources in the world, in this research groundwater potentiality of the Shirkuh granitic rocks located in southwest of Yazd city was evaluated. The area is known as the main recharge zone of the alluvial aquifer of Yazd-Ardekan plain. In this study the effective parameters in groundwater potentials were firstly determind. They are included as lineament density, drainage density, rainfall, lithology, topographic slope and vegetation cover laxyers which were prepared using RS and GIS softwares. Having been provided thematic maps, two knowledge-driven strategies including continuous fuzzification and multi-criteria evaluation models were used to combine thematic maps. In fuzzy model, after fuzzification of the maps in GIS environment, the thematic maps were combined using various fuzzy operators. After the evaluation, Gama was selected as the best operator for combination and providing the final map. In this method about 20% of the studied area was identified as the groundwater potential zones. In multi-criteria evaluation model, after weighting the maps with the expert opinion, the thematic maps were combined using weighted linear combination method and the groundwater potentiality map was created. After validation the results of the both models by water resources location and discharge, a good correlations were found in in multi-criteria model and so this method was applied in groundwater potential mapping of the region. In this method about 40% of the studied area was detected as good and very good potential zones which are locate mainly in the valleys (the weathered granitic hardrock) and the central part of the granite massive rock (the fractured hardrock).