Vertical source/sink strengths distributions and net flux of carbon dioxide (CO2) within and above a broadleaved Koreanpine forest canopy were modeled by inverse Lagrangian dispersion analysis method using only mean concentration profiles measured in Changbai mountain research station of China. The model results compared well with eddy covariance CO2 flux measurements above the canopy, and the average correlation coefficient is 0.89; however, the model overestimated nocturnal CO2 flux about two to three times larger than those measured results. The time-depth evolutions of CO2 source/sink strength and the relationship between CO2 flux and photosynthetically active radiation (PAR) were also discussed.