Abstract: 【Objective】 To investigate the response characteristics of growth morphology and physiological traits of Cyphomandra betacea seedlings to changing precipitation patterns， which could provide theoretical basis for water management of Cyphomandra betacea at the seedling stage. 【Method】 One-year-old Cyphomandra betacea seedlings were used as experimental materials. A two-factor experimental design was adopted， with 2 precipitation intervals： natural precipitation interval of 3 d （T） and extended precipitation interval of 6 d （T+）. Taking the average precipitation from April to July in Kunming as the control （W）， 2 precipitation levels were set： 40% increased precipitation （W+） and 40% decreased precipitation （W-）， resulting in a total of 6 precipitation treatments （WT， WT+， W+T， W+T+， W-T， W-T+）. Indexes including biomass of different organs， leaf， and root morphology， chlorophyll content， and plant carbon （C）， nitrogen （N）， and phosphorus （P） contents of Cyphomandra betacea seedlings were measured. The types of growth relationships among organs were analyzed， and a comprehensive evaluation was conducted using the membership function method. 【Result】 Precipitation had extremely significant effects on root， stem， leaf， and total biomass of Cyphomandra betacea seedlings （P<0.01， the same below）， and excessive precipitation was unfavorable to biomass accumulation in various organs of Cyphomandra betacea seedlings. A moderate increase in precipitation was beneficial to leaf growth and development， while a moderate increase in precipitation combined with an extended precipitation interval promoted root morphological development of Cyphomandra betacea seedlings. Precipitation exerted extremely significant effects on C， N， and P contents of Cyphomandra betacea seedlings under all treatments， and at the same precipitation interval， C， N， and P contents of Cyphomandra betacea seedlings generally increased with rising precipitation， C∶N， C∶P， and N∶P all decreased as precipitation increased. Total chlorophyll content was positively correlated with leaf traits in Cyphomandra betacea seedlings， except for leaf perimeter and leaf length in July. In April， stem-root and leaf-root biomass showed allometric growth relationship under different precipitation intervals， whereas leaf-stem biomass exhibited isometric growth relationship； in May and June， leaf-root biomass showed isometric growth under all precipitation intervals. The average membership function value was the highest under the W+T+ treatment in May， indicating that this treatment was the optimal simulated precipitation regime. 【Conclusion】 Increasing precipitation has promoting effects on the leaf morphology development， root growth， and nutrient accumulation of Cyphomandra betacea seedlings. Appropriate extension of the precipitation interval can promote root growth but is not conducive to leaf morphology development. In field production and management， it is recommended to adopt increased water usage and 6 d precipitation interval in the dry season to alleviate the shortage of water supply. In the rainy season， natural precipitation combined with artificial drainage is suggested to regulate the soil oxygen environment， combined with appropriate topdressing of nitrogen fertilizer. Under greenhouse cultivation， water management of Cyphomandra betacea seedlings can be implemented by simulating the precipitation vo-lume of 178.82 mL and precipitation interval of 6 d.