A method, an apparatus, and a computer program for analyzing performance of a network application program are provided. The method for analyzing performance of a network application program which operates at a controller in a software defined networking (SDN) environment may include receiving identification information of the application program, flow information, and network configuration information of a network controlled by the controller, emulating a virtual network using the network configuration information, executing the virtual network using the flow information, measuring a time, when a virtual controller processes a flow, on a function basis, extracting information corresponding to the identification information of the application program from the measured result, and analyzing a performance degradation factor of the application program using the extracted information. According to an embodiment, a network manager automatically searches for a critical path and a hotspot using a conventional profiling scheme.