Results of numerical simulation of currents in the western North Tropical Pacific Ocean by using a barotropic primitive equation model with fine horizontal resolution agreed well with observations and showed that the Mindanao Cyclonic Eddy located north of the equator and east of Mindanao Island exists during most of the year with monthly (and large seasonal) variations in scope . strength and central location . In June , an anticyclonic eddy occurs northeast of Halmahera Island, strengthens to maximum in August , exists until October and then disappears . The observed large-scale circulation systems such as the North Equatorial Current . the Mindanao Current and the North Equatorial Countercurrent are all very well reproduced in the simulations. Results of numerical simulation of currents in the western North Tropical Pacific Ocean by using a barotropic primitive equation model with fine horizontal resolution agreed well with with observations and showed that the Mindanao Cyclonic Eddy located north of the equator and east of Mindanao Island exists during most of the year with monthly (and large seasonal) variations in scope. strength and central location. In June, an anticyclonic eddy occurs northeast of Halmahera Island, strengthens to maximum in August, exists until October and then disappears. The observed large-scale circulation systems such as as the North Equatorial Current. the Mindanao Current and the North Equatorial Countercurrent are all very well reproduced in the simulations.