[Objective] Rainfall interception by forest canopy is an important eco-hydrological process of forest. We aimed to model the canopy interception process by chinese fir forest in Jinggangshan nature reserve in order to provide some bases for relevant researches with respect to eco-value evaluation of forest, protection and management of water resources, and environment protection of this region, et al. [Methods] A model developed by Yi Chuixiang et al was refined. And it was calibrated and validated by observed interception data in a chinese fir forest. [Results] The model calibration showed that extra interception as a dependent variable is a power function of remained-rainfall, defined as the result of atmosphere rainfall minus the value intercepted by plant leaves. The calibrated model performed better than those empirical models and is comparable to Gash model in similar researches. The effective coefficient and relative bias in predicting single rainfall event were 0.9 and 6.49%, respectively. [Conclusion] After calibration, the improved model in our study can be used for simulating canopy interception by chinese fir forest in the research region.