The objective of the present investigation was to study the effect of drought stress, UV-B radiation and the combined effects of UV-B and drought stresses on two cultivars of gourd (mashhadi and hamadani) seedling. the gourd plants were grown with diurnal regime of 16h light and 8h dark and temperature of 22/260C (night/day). The relative humidity was 60% and average of photosynthetically active radiation was 150 µmol.m-2.S for 25 days. Then, 25-days-old seedlings were divided in to four groups: the control and three groups subjected to stress conditions: UV-B radiation and drought stress conditions, UV-B radiation and drought stresses combined. Results showed that shoot and root length, shoot and root dry and fresh weight, leaf total area, leaf RWC, chlorophyll a, b and carotenoid contents which were irradiated either with UV-B, drought stress or combined of two stresses have reduced significantly when compared with control. The physiological parameters indicate that with this experiment situation UV-B stress has stronger stress effectors than drought on the growth of seedling of both cultivars. The results suggested that co-stresses of supplementary UV-B radiation and drought synergistically functioned and one of them could alleviate the inhibitory effects of another under the condition of arid and semiarid loessial soils.