ABSTRACT This study presents seismic hazard analysis that aims to estimate peak base acceleration of Yogyakarta for 500 – year return period earthquake. The seismic hazard analysis by probabilistic seismic hazard analysis (PSHA) method using EZ FRISK program that models fault sources in three dimensional representation. The seismic sources considered are the acknowledge earthquake potential to a depth of 200 km within radius of 500 km from Yogyakarta. This study utilizes logic tree to cover uncertainties within one method of earthquake assessment. Seismic parameters are calculated by the method of Kijko & Sellevoll  and Weichert. Three attenuation models are chosen for determination of the ground motion. The attenuation model of Youngs is selected to represent the subduction environment of Java and attenuation models of Boore et al.  and Sadigh et al. are selected to represent shallow crustal fault. The result of the analysis shows that its peak base acceleration is 0.33 g for 500 – year return period. 
 
Keywords: Probabilistic seismic hazard analysis, peak base acceleration, ground motion, three dimensional seismic source