Abstract: The effects of several kinds of plant hormones on heterotrophic culture of Chlorella vulgar/s were researched. The results showed that plant hormones such as IA_A, IBA and 6-BA could all stimulate the heterotrophie growth of Chlorella vulgaris in the heterotrophie culture to degrees. Within the culture time of 36 h, 20 mg/L IA.A or IBA had the maximum stimulating effect on the heterotmphic growth. 100 mg/L L4A or IBA inhibited the heterotrophic growth within the culture time of 36 h but stimulated it after 36 h, and in the end the largest Am net increase was.obtained by the treatment of 100 mg/L IAA or IBA. 6-BA enhanced the heterotrophic growth with the optimum concentration being 0.1 mg/L. The combination of IBA with 6-BA also stimulated the beterotrophie growth, but the stimulating effect was different from the simple adding effect of beth IBA and 6-BA. The effect of the combination of 5 mg/L IBA with 6-BA was identical to the solely 6-BA effect. The combination of 20 mg/L IBA with 1 mg/L 6-BA had a greater stimulating effect than that of the combination of 20 mg/L IBA with 0.1 mg/L 6-BA. Moreover, within the culture time of 36 h, the effect of the combination of 100 mg/L IBA with 0.1 mg/L 6-BA was greater than that of the combination of 100 mg/L IBA with 1 mg/L 6-BA. However, after 36 h, the opposite was true. Furthermore, the results indicated that the combination of IBA equal to or more than 20 mg/L with 6-BA inhibited the uptake of glucose by the algae during the early middle culture stages and enhanced the uptake during the middle –late culture stages and that the combination of IBA with 6-BA stimulated the uptake of NO3- by the algae.