Abstract: We applied a L₁₆(4⁵) orthogonal experimental design to determine and compare the biomass, chlorophyll content, chlorophyll fluorescence parameters, and photosynthetic characteristics of Tabebuia chrysantha (Jacq.) Nichols seedlings under different combinations of rooting powder (GGR), indole acetic acid (IAA), and paclobutrazol (PP₃₃₃). The effects of the different combinations of plant exogenous hormones (GGR, IAA, and PP₃₃₃) on the growth and photosynthesis of T. chrysantha seedlings were used to derive the optimal concentration combination. Results showed that fresh weight and dry weight were highest under Treatment 11 (GGR 400 mg/L, IAA 400 mg/L, PP₃₃₃ 400 mg/L) compared with the other treatments. Among the three plant exogenous hormones, GGR played a leading role in the increase in fresh and dry weights, whereas IAA and PP₃₃₃ did not have a significant effect. The net photosynthetic rate, stomatal conductance, transpiration rate, chlorophyll content, and chlorophyll fluorescence parameters of seedlings were also highest under Treatment 11, whereas intracellular carbon dioxide concentration was lowest. Results also showed that IAA played a leading role in the net photosynthetic rate, stomatal conductance, transpiration rate, potential activity of photosynthesis system, maximum light energy conversion efficiency, and chlorophyll content of T. chrysantha seedlings, whereas the effects of GGR and PP₃₃₃ were not obvious. Comprehensive analysis further showed that the appropriate concentration combination of different exogenous hormones was that of Treatment 11, under which the quality of T. chrysantha seedlings was optimal.