Tobacco (Nicotiana tabacum L.) plants were cultivated in phytotron set at relatively low temperature (daily average 16.5 ℃), normal temperature (daily average 23.5 ℃) and relatively high temperature (daily average 30.5 ℃), and the effects of different temperature on growth, development and photosynthesis of tobacco plants were investigated. The results showed that：(1) Compared with the plants under normal temperature, the plants grown under the relatively higher and lower temperatures decreased the plant height, leaf length, width and showed an inhibiting effects on tobacco plants to some extent. (2) Plants under relative higher and lower temperature reduced the net photosynthetic rate (P_n), intercellular CO₂ concentration (C_i), stomatal conductance (G_s), transpiration rate (T_r), maximum quantum yield of PSⅡ photochemistry (F_v/F_m), quantum efficient of PSⅡ (Φ_PSⅡ), photochemical quenching (q_p), Rubisco activity, but increased the minimal fluorescence of darkadapted state (F₀) of tobacco leaves. Tobacco plants grown under longterm relative higher and lower temperatures both inhibited the growth by partly damaging or inactiving the photosynthetic apparatus, and reduced the photosynthesis efficiency of tobacco plants to some extent. Longterm daily average temperature at 23.5 ℃ could be the optimal temperature for growth and photosynthesis of tobacco plants.