Photosynthesis and respiration of leaf and root of field grown Panax ginseng were investigated according to aerial part sensecence. No apparent photosynthesis activity was detected in senescenced leaf(less than 0.7mg total chlorophyll/g FW) and leaf dark respiration was consistent relation with senescence. Leaf respiratory Q$_{10}$ consistently increased with senscence. Root respiration and Q$_{10}$ tended to decrease with aerial part senescence only in the range of optimum temperature of leaf growth. Apparent photosynthesis or respiration of leaf was negatively or positively correlated, respectively with the increase of air temperature. Root respiration with temperature was well accordance with Arrhenius plot which was not consistent with aerial part senescence. Accelerated senescence may be recommendable for better root yield unless any reserve in stem or leaves contributes to root through translocation.