This study was conducted to find out the effects of water temperature on the growth, antioxidant enzyme activity, and immune enzyme activity of juvenile sea cucumbers Holothuria scabra. We cultivated healthy individuals with an average body weight of (1.70±0.24 g) at three temperatures: low temperature at 23 ℃, control at 28 ℃, and high temperature at 33°C in temperature-controlled tanks for 30 d. The specific growth rate of H. scabra juveniles was measured every 10 d. Juvenile H. scabra body walls, coelomic fluid, intestines, and respiratory trees were collected to determine superoxide dismutase (SOD), catalase (CAT), alkaline phosphatase (AKP), lysozyme (LZM), and malondialdehyde (MDA) content. The results showed that: (1) The SGR_0-30 of the control group was significantly higher than that of the high-temperature and low-temperature groups (P＜0.05), and the high-temperature group exhibited a significantly higher value than that of the low-temperature group (P＜0.05), indicating that long-term low temperature had a greater impact on juveniles than long-term high temperature. (2) In the low-temperature group, SOD, AKP, and LZM activity and MDA content in the coelomic fluid were not significantly different from those in the control group at 0 d, and SOD, CAT, and AKP activity were significantly higher than those in the control group at 30 d (P＜0.05). SOD, CAT, and LZM activity, and MDA content in the body wall were not significantly different from those in the control group at day 0; however, SOD, CAT activity, and MDA content were significantly higher than those in the control group at day 30 (P＜0.05). All enzyme activities in the intestine were significantly higher than those in the control group at 0 d (P＜0.05), except for MDA content. Then, only MDA content was significantly higher that of the control group at 30 d (P＜0.05). All indicators in the respiratory tree were significantly higher than those in the control group at 0 and 30 d (P＜0.05). The results showed that the coelomic fluid and body wall of juvenile H. scabra needed to cope with oxidative stress caused by prolonged low temperatures, while the intestine had to deal with oxidative stress from short-term low temperatures, and the respiratory tree had to adapt to oxidative stress from both short-term and prolonged low temperatures. (3) In the high-temperature group, SOD, CAT, and AKP activity and MDA content in the coelomic fluid and body wall were significantly higher than those in the control group at 0 d (P＜0.05). No indicators showed significant differences from those in the control group at 30 d. CAT activity in the intestine was significantly higher than those in the control group on day 0 (P＜0.05), and all indicators were significantly higher than those in the control group on day 30 (P＜0.05). All indicators in the respiratory tree were significantly higher than those in the control group at 0 and 30 d (P＜0.05); CAT content and MDA content were significantly higher than that in the control group (P＜0.05). This suggests that the coelomic fluid and body wall primarily faced oxidative stress from short-term exposure to high temperatures, whereas the intestine and respiratory tree had to deal with both short-term and prolonged high-temperature stresses. (4) Antioxidant and immune enzyme activities in the four tissues of juvenile sea cucumbers were negatively correlated with SGR, indicating that the increase in antioxidant and immune enzyme activities conflicted with rapid growth, resulting in a significant decrease in SGR. In conclusion, both prolonged low and high temperatures generated oxidative stress in juvenile H. scabra, and juvenile H. scabra had greater adaptability to high temperatures.