Abstract:[Objective] To study the effects of paclobutrazol(PP333) and rooting powder(GGR6) on chlorophyll fluorescence parameters of Cerasus humilis, in order to provide scientific and theoretical basis for strong seedling cultivation techniques of C. humilis seedlings.[Methods] Single factor analysis was used to study the 1-year-old C. humilis seedlings, which were respectively dipped into PP333 and GGR6 with a concentration of 0, 50, 100, 150 and 200mg/L, and the fluorescence was measured by PMA2500.[Results] With the increasing concentration of PP333 and GGR6, the electron transfer efficiency (ETR), actual photochemical quantum efficiency (ΦPSⅡ), photochemical quenching (qP) and maximum photochemical efficiency (Fv/Fm) were increased, while the non-photochemical quenching(qN) decreased.[Conclusion] The best plant growth regulator was GGR6, and the optimal concentration was 200 mg/L. With the same concentration, the effect of GGR6 on the fluorescence parameters of C. humilis seedlings was better than that of PP333.