This study aimed to examine the relationship between topographic factors and the photosynthetic rate parameter of a process-based growth model for sugi (Cryptomeria japonica) planted forests. The site-specific photosynthetic parameters were estimated using stand growth data derived from 30 permanent plots established in the Tano Forest Science Station (University of Miyazaki) by Bayesian calibration. The estimated plot-specific photosynthetic rates were related to the following topographic factors: solar radiation index, hydrological upslope contributing area index, vertical and horizontal exposure index, and average slope gradient. Significant but weak correlations were found between the plot-specific photosynthetic rate and all topographic factors except solar radiation index.