Abstract: Kastamonu city center falls in the first degree earthquake zone in the latest map of 1996 which is still inforce. 46 percent of the surface area of Kastamonu province is in the first degree hazard zone, 22 percentin the second degree hazard zone, 24 percent in the third degree hazard zone and 8 percent in the fourthdegree hazard zone. Although the city center is located the first degree hazard zone, there are very fewstudies on seismicity and seismic hazard for this region.  The seismicity of Kastamonu has been investigated by using the earthquakes with a magnitude of 4.0 greater that occurred in a region with a 150-km radius for the time interval 1900-2011. Epicentersof earthquakes were relocated to make a correlation with the active faults and to determine the seismicactivity in the region. The earthquakes are particularly concentrated on the active tectonic lines such asthe North Anatolian Fault Zone, the Dodurga fault, the Eldivan – Elmadağ tektonic junction, the Merzifonfault and the Taşova – Çorum fault zone. The aim of this study is to predict probability of earthquake occurrences and return periods for Kastamonuand near surroundings by using the earthquakes with a magnitude of 4.0 greater (M >=4.0) thatoccurred in regions with 50, 100 and 150 km radius for the time interval 1900 – 2011. Hence a statisticalaspect based on Poisson model and a classical linear magnitude-frequency relation of Gutenberg-Richterwere used for each region. The earthquake occurrence probabilities for investigated area were calculated for some periods of T =10, 20, 30, 40, 50, 75, 100 years and for magnitudes of M = 5.0, 5.5, 6.0, 6.5, 7.0, 7.5. Within a radius 150km of Kastamonu city center, the occurrence probability and recurrence period of an earthquake with amagnitude of 7.5 greater in 100 years were calculated as 75 percent.