Abstract: Pakchoi seeds were taken as experimental material, and 200 g·L^-1 PEG 6000 was used as artificial stress simulation.The effects of seeds soaking in seaweed extract and spraying on the leaf with different concentrations on germination characteristics, seedling growth and physiological characteristics were studied, in order to provide reference for the application of seaweed extract under drought stress.The results showed that drought stress obviously decreased the germination energy, germination percentage, germination index, vigor index, plant height, stem diameter, leaf area, dry weight of ground and root, chlorophyll content, relative water content, and root activity, increased MDA content and relative electrical conductivity significantly.Seaweed extract could significantly promote seed germination and seedling growth of pakchoi under drought stress, reduce MDA content and relative conductivity, improve chlorophyll content, relative water content of leaves and root activity.The best treatment of seeds soaking was 1 500 times diluents,and the best treatment of spraying was2 000 times diluents.These illustrated that the exogenous seaweed extract could reduce the inhibition effect of drought stress on seed germination and seedling growth,improve the stress resistance of pakchoi,and promote seedling growth.