Abstract: Based on the measurement above and below forest canopy and meteorological data,the spectral characteristics of solar radiation in broadleaved Korean pine forest in Changbai Mountain was analyzed.The results show that the photosynthetically active radiation(PAP)coeffcients of total radiation,direct radiation and scatter radiation changed daily and yearly,with an annual averages of 0.46,0.43 and 0.56 respectively.The average reflectivity,transmissitvity and absorptivity of single leaves of different tree species in Korean pine forest were 27.0%,23.4%,49.6% respectively.Single leaves nearly absorbed all of the ultraviolet radiation(UV) and 71.8% of photosynthetically active radiation,but transmitted 9.6% and reflected 18.6%.As for near-infrared radiation (NIR),the reflectivity and transmissitivity of leaves were a little less than the absorptivity.The forest canopy absorbed 93.9% PAR and 94.1% UV,but reflected and transmitted less.It absorbed 59.2%,reflected 26.3% and transmitted 14.4% NIR.