Abstract: The interception process of rainfall in a forest canopy is very important in water resource cycles of forest watershed．Most studies have considered the relationship between the interception in one or several rainfall events and precipitation without thorough consideration of the characteristics of rainfall density and vegetation‚ and therefore little of the study results can be used in a distributed rainstorm- runoff model．After carrying out some simulation experiments in the lab‚the authors obtained data of interception process in unattached events with different rainfall densities and leaf area indexes．Based on the data‚the relationship between rainfall density and the maximum interception per unit leaf area index is quantified．The change of the interception ratio with the canopy humidity is also identified．Hence‚an interception model‚in which interception is calculated using rainfall density and leaf area index‚is constructed with the consideration of canopy humidity． Finally‚with the simulatidon experiment‚it is concluded that the precision of the model is 91∙5％．