Ｏｂｊｅｃｔｉｖｅ　To explore the effects of ambient temperature on spatial memory, weight, and activity.　Methods　Twenty four mice were randomly divided into three groups(n=8): hot group (38 ℃ for 6 h), cold group (4 ℃ for 6 h), and control group (20 ℃). Intellicage for mice was used to continuously test spatial memory and mice weight was measured every day.　Results　Compared with control group, the spatial memory of mice in hot group was significantly improved after 3-6 days' temperature treatments with corner preference increase from (74±8)% to (82±7)% at Day3, (71±4)% to (87±12)% at Day4, (67±6)% to (80±9)% at Day5, (73±7)% to (84±6)% at Day6 (P<0.05), while body weight tarted to decrease markedly until Day 8 [Day 5 (27.5±1.2) g vs (29.1±0.7) g，Day 6 (28.6±1.0) g vs (30.1±0.7) g，Day 7 (28.7±1.0) g vs (30.4±0.8) g，Day 8 (29.9±0.5) g vs (30.6±0.5) g] (P<0.05). Cold temperature did not affect the spatial memory and body weight of mice. Both hot group and cold group mice showed decreased gross activity 2-4 days' [Day 2 (361±74) s vs (576±88）s, Day 3 (487±104)s vs (631±81）s, Day 4 (532±88) s vs (678±35）s] (P<0.05).　Conclusions　Our study showed that ambient temperature, especially hot environment, could affect the spatial memory, body weight, and activity of mice.