Abstract: We applied the orthogonal experiment method of two factors and five levels to study the combined effects of temperature (16.0 ℃, 20.0℃, 24.0 ℃, 28.0 ℃, 32.0 ℃) and gravity (1.016 0, 1.020 0, 1.024 0, 1.028 0, 1.032 0) on survival and growth of Lutraria sieboldii juveniles in the laboratory. The results show that: 1) In the optimum gravity range, the suitable temperature range of juveniles survival was 17.0~32.7 ℃; the optimum temperature range of survival was 24.0~28.0 ℃; the suitable temperature range of growth was 16.4~32.7 ℃; the optimum temperature range of growth was 24.0~30.0 ℃. 2) In the optimum temperature range, the suitable gravity range of juveniles survival was 1.016 5~1.031 8; the optimum gravity of survival was 1.024 0; the suitable gravity range of growth was 1.016 3~1.031 8; the optimum gravity range of growth was 1.021 3~1.028 6. 3) There were combine effects between temperature and gravity. The suitable and optimum temperature as well as gravity ranges of juveniles decreased gradually with gradient moving to the two ends.