Sumatra Island is an island in Indonesia, that has a severe impact to earthquake hazard. That is because in the western part of the sumatra island have the subduction zones which is a meeting between Indo-Australian plate which is embedded under the Eurasian plate into the direction tilted about 45o, and move around 50-70 cm/year (Prawirodirjo, et.al, 2000). This condition led to the forming of the Sumatra Faults from Sunda Strait to the Andaman Island at the west side of Aceh province. The Sumatra Faults consists of 19 segments and a total length of 1,900 km (Sieh and Natawidjaya, 2000). The movement of Indo-Australian plate has continually caused stress along the subduction zone and also pose earthquake hazard at around Sumatra Faults areas. Earthquake caused by the fault activity has occurred several times in Indonesia and it cause building damages, such as Liwa earthquake on February 16th, 1994 and Solok Earthquake on March 6th, 2007 due to Sumatra Fault activity. In this research, analysis of earthquake probability occurance caused by the Sumatra Faults activity use the Conditional Probability Method. History of earthquakes taken in this research is of the earthquake intensity with magnitude M > 4.5 SR, based on the intensity of the quake damage. The analysis showed that 19 Segment on Sumatra Fault have a likelihood of occurrance Likely level, then there are 3 active segments respectively - were the Sunda Fault, Fault and Fault Tripa in Aceh.