IN THIS PAPER, USING A FULLY NONLINEAR BOUSSINESQ MODEL, PROBABLE TSUNAMIS CAUSED BY MSZ EARTHQUAKES IS SIMULATED AND THEIR EFFECT AND PROBABLE FOLLOWING RUN-UP ON CHABAHAR BAY’S COASTS, MOST IMPORTANT POPULATED REGION OF IRANIAN COASTS IN OMAN SEA, IS EVALUATED. UNLIKE PREVIOUS STUDIES WHICH CONSIDERED ONLY A GLOBAL MODEL WITH LIMITED AREA FOR SIMULATING MAKRAN TSUNAMIS, THE PRESENT RESEARCH DEFINES A LOCAL MODEL WITH FINER NETWORKS IN THE CHABAHAR BAY IN ORDER TO RECORD TSUNAMI RUN-UPS THIS REGION. THE SIMULATION RESULTS REVEALED THAT ABOUT TWENTY MINUTES AFTER AN EARTHQUAKE IN MAKRAN ZONE AND CHABAHAR BAY NEIGHBORHOOD, THE TSUNAMI WAVES REACH CHABAHAR PORT. WITH THE INCREASE OF EARTHQUAKE MAGNITUDE, THE WAVE’S HEIGHT AND INUNDATION INCREASES IN COASTS, IN A WAY THAT IN THE MOST CRITICAL SCENARIO (WITH THE MAGNITUDE OF TORQUES NINE), THE WAVE’S HEIGHT IN CHABAHAR PORT REACHES TO TEN METER. NONETHELESS, BECAUSE OF ROCKY COASTS AND THE HIGH LEVEL OF LAND, INUNDATION IN CHABAHAR PORT IS NOT TOO MUCH AND IN THE MOST CRITICAL SCENARIO IT REACHES TO 500 METER. ON THE OTHER HAND, KENARAK PORT IS PLACE BEHIND THE WESTERN CAPE OF BAY AND RECEIVES TSUNAMI WAVES WITH LOWER HEIGHT AND EVEN IN THE MOST CRITICAL SCENARIO, THE TSUNAMI WAVES WITH THE HEIGHT OF 4 METER CANNOT RESULT IN INUNDATION IN THIS PORT.