Abstract
Hydraulic systems of injection molding machine are modelled and simulated with AMESim which is a commercial program. Detail models of hydraulic components are simulated and simulation results are evaluated with maker's test results in catalog. Sub system models which is divided according to functional operation are made and its analysis results shows how design parameters work on operational characteristics like cylinder speed, cylinder displacement, pressure, flow rates at each node and so on. Total circuit model is also made and analyzed. The prediction made by simulation will be used design of hydraulic systems of injection molding machine.