Abstract: A profile instrumentation method and a profile data collection method in which mapping between an original code and a corresponding transformed code can be easily performed during compilation so as to perform profiling in a parallel processing system. In the profile instrumentation method, in order to grasp the behavior of a program for a parallel computer written in a sequential format using an original source code, an instrumentation code for instructing collection of profile data during execution of the program is inserted into a transformed code of the program which has been obtained by optimizing transformation during compilation. In this method, a profile initialization processing is performed so as to collect information regarding the original source code of the program before the optimizing transformation by the compilation. This method is used to collect profile data (e.g. the execution time, iteration count, etc.