In order to conserve energy consumed by heat source equipments for air-conditioning, chillers, cooling/chilled water pumps and cooling tower fans are increasingly equipped with inverter to improve their energy efficiency in recent years. And also, heat recovery is being designed to collect the heat from heated cooling water in order to save energy for heat supply. But the operating method is not established and he effect of heat recovery equipment is not verified either. In the previous paper the optimal operation for simple heat source system is proposed and verified as follow: 1)the development and verification of simulation model, 2)the comparison to ideal optimal operation, 3)dicussion of CT selection in design period. In this research, the optimal operation of a complicated subsystem rth complex cooling towers (CT), and heat recovery equipment studied as follows:1)the development and verification of simulation Rhode 1, for each equipment, 2)the comparison between present operating simulation and cooling-water-temperature-optimized oper-ating simulation with heat recovery, 3)comparison between present operating simulation and ideal-optimized operating simulation without heat recovery, 4)Discussion on the effect of heat recovery by evaluating COP of heating process.