PURPOSE: To provide a synchronous processing method for a parallel processing system capable of executing parallel processing while guaranteeing the execution order of plural procedures.

CONSTITUTION: After executing a certain procedure, a 1st process 101 adds information necessary and sufficient for executing the succeeding procedure tightly relating to the procedure concerned to data 104 to be processed and inserts the data 104 into a queue 103. A 2nd process 102 extracts the data 104 from the queue 103 and indirectly the succeeding procedure tightly relating to the procedure makes access to concerned based upon the information added to the data 104 to execute the succeeding procedure.