A short-term heuristic method of pumped（hydroenergy）storage plants（PSP）operation for regulating peak loads of multiple power grids has been developed based on the actual project of East China Grid（ECG）.The power generation or pump power of PSP is decided by the maximum or minimum value of the total load at each iteration.And power generation or pump power is further allocated between power grids using two strategies，known as power cutup and combination optimization.This process is repeated till the desired target objectives of PSP are satisfied.The case results over ECG show that the proposed method is able to solve the load distribution problem of PSP between multiple power grids.