As the rising of people growth number, the number of private vehicle ownership and the other system of mass transportation  will cause traffic problem specially at the intersection. Yogyakarta is a city of student and also a developing city that has that problem. One of the intersection of yogyakarta which need to evaluate and to has a performance rising is unsignalized intersection of Jalan wates km 5 Gamping. This intersection is an unsignalized intersection that connect national highway and city highway. Therefore it is necessary to analyze the performance of the existing condition of the intersection. The purpose of this study is to know the performance of the unsignalize intersection of jalan wates km 5 Gamping on the exsisting condition and also to know the right alternative way to solve the problem. This research used descriptive method, quantitative, and qualitative. The data which is obtained from primary survey on the field at peak hour in the morning, day, and afternoon, and then be analyzed by using Indonesia Highway Capacity Manual 1997 and PTV Vissim. The result of this study showed that the unsignalize intersection on jalan wates km 5 in the existing condition using IHCM and PTV Vissim showed that the performance of the intersection is not good enough. The analysis using IHCM showed that the capacity is 4592 pcu/h, (degree of saturated (DS) 1.24 delay 53,391 sec/pcu, queque probability 62.696% - 128.329% and level of service F. The anlysis using PTV Vissim showed that delay for the north approach = 8,20 sec/vehicle. East approach = 9,43 sec/veh. South approach = 4,82  sec/veh. And west approach = 68,22 sec/veh. While for queue of north approach = 15,57 m, east approach = 67,83, south approach = 11,15 m, west approach = 181,533 m with the level of service of F. In this research, there are three solution. First is installing the median on the main highway, second is activating one way system for minor highway, and third is installing the median on the main highway, decreasing obstacle aside and activating one way system for minor highway. The right alternative of problem solving for unsignalize intersection of Jalan Wates km 5 is installing the median on the main highway, decreasing obstacle aside and activating one way system for minor highway at peak hour. Therefore there are no flow of vehicle from the minor road to the intersection. So that the capacity become 6949 smp/jam degree of saturated 0.78, delay 12.64 sec/smp and queue probability = 24.789% - 49.392% with level of service of C. The analysis using PTV Vissim showed that delay of east approach = 2.35 sec/veh. West approach = 8,75 sec/veh. While for the east queue = 32,68 m and west queue = 175,22 m with level of service of B. 
Keywords: unsignalize intersection, IHCM, PTV Vissim, Level of Service