From 2004 to 2006, a Pinus tabulaeformis plantation which was 33 years old was observed to study canopy interception, throughfall and stenflow in western reservoir of Miyun of Beijing. The results showed that the average ratio of interception, throughfall and stenflow were 31.67%, 67. 65% and 0. 68%, respectively. The rates of interception dropped off rapidly and inclined to the terminal value with the increasing amount of precipitation. The relationship between the amount of canopy interception and precipitation was power function. There was a prominent and positive correlation between throughfall amount and precipitation amount. Stemflow contributions to total fluxes of rainfall are particularly small. Stemflow was close correlation with precipitation amount, average rain density and the maximal rain density in thirty minutes by partial correlation.