The invention discloses a method of reporting performance data in a mobile communication system, which is appropriate for switching various mobile communication systems or collecting other performance data with over CPU statistics, comprising the following steps of: undergoing extension based on a storage space of original performance data in each CPU; the storage space of original performance data is a memory space capable of storing the performance data of N cells; N is the greatest cell number managed by the CPU; triggering the cell by service process so as to report the performance of thecell; obtaining the performance data of the triggered cell in the storage space of the performance data; reporting time periodically to the performance data of all the triggered cells reported later.With the plan of the invention, memory resource can be applied with the at least amount but higher efficiency, without message transformation over CPU, so as to satisfy immediacy and reliability of the performance data, with simple and convenient method, and strong extendibility.