Controlled experiments were conducted to investigate the effect of temperature, drought and their interaction on seeds germination and seedling growth, aiming to understand how they adapt to the seasonally drought and cold in spring at seed germination stage, for giving base to population resume and cultivation of Platycodon. The results of a two-way ANOVA showed that temperature, drought and their interaction significantly affected the seed germination and seedling growth. Seed germination was optimal at the fluctuating night/day temperature regime of 10/20℃ and constant temperature range from 15℃ to 25℃ in the concentration of 0-10% PEG (except for the concentration of 10% PEG at 20℃), with more than 62.7% of seeds germinated, while seed germination percentage was significantly decreased by the concentration of 15% PEG. Seed germination was significantly inhibited and their initiatory time was delayed at 10℃, germination percentage was increased and then decreased with the increasing of drought stress, while both germination percentage and vigor index all declined at other temperatures. Root length, shoot length and fresh weight were declined with the decreasing of temperature, and root was more sensitive than shoot to changes of temperature.