We studied the effects of alternate respiration pathway on chlorophyll content and fluorescence characteristics of Angelica sinensis seedlings by pot experiment in greenhouse to explore the role of alternate respiratory pathway in the response of A. sinensis under low temperature (4 ℃ and -7 ℃). It was found that, with the decrease of temperature and the increase of low temperature time, the chlorophyll content, actual photochemical efficiency ［Y(Ⅱ)］, photosynthetic electron transfer rate (ETR), and photochemical quenching coefficient (qL) of A. sinensis decreased, while the nonphotochemical quenching coefficient (NPQ) was increased. Meanwhile, low temperature stress also resulted in a significant increase in the alternate respiratory capacity of the A. sinensis seedlings. Under low temperature stress, compared with the A. sinensis seedlings without chemical treatment, the chlorophyll content, Y(Ⅱ), ETR and qL of A. sinensis seedlings pretreated with the inhibitor of the alternate respiratory pathway ［1 mmol·L^-1 salicylhydroxamic acid (SHAM)］ decreased further, but NPQ increased significantly, and the lower the temperature was, the greater the range of rise and fall was. These results indicate that low temperature stress significantly inhibited the chlorophyll synthesis and photochemical properties in the leaves of A. sinensis seedlings, and the alternate respiratory pathway has protective effects on PSⅡ photochemistry and chlorophyll biosynthesis of A. sinensis seedlings under low temperature stress.