Abstract: Purple rape was used to study the effect of seaweed fertilizer on the morphological and physiological indexes. By applying different concentrations of seaweed fertilizer solution (400, 800, 1200, 1600, 2000 and 2400 times), the authors determined the morphological indexes (plant height, leaf number, leaf length, leaf width, fresh weight and dry weight) and physiological indexes (chlorophyll, anthocyanin, soluble sugar, soluble protein, Vc and nitric nitrogen content) of purple rape. The results showed that the seaweed fertilizer was helpful in increasing the biomass of purple rape, and the highest biomass was observed in T3 (1200 times), under which the fresh weight was 1.5 times higher than that of control, and the root/shoot ratio was better than that of other treatments. Lower concentrations of seaweed fertilizer could increase plant height, and the plant height of T4 (1600 times) was 1.3 times higher than that of control. The values of water content, anthocyanin content, soluble protein content and Vc of T3 and T4 were the highest; the chlorophyll content of T4 (1600 times)- T6 (2400 times) was the highest. The nitrate nitrogen content was less than 1000 mg/kg in all treatments, and T6 had the lowest nitrate nitrogen content, and it decreased with the increase of dilution ratio of the fertilizer. The best quality of purple rape was observed in the dilution ratio of 1200-1600 times of seaweed fertilizer.