The experiments were conducted to determine the effects of gibberellin and naphthyleneacetic acid on growth of Skeletonema costatum, the results showed that 1.25mg/L gibberellin or 0.75mg/L naphthyleneacetic acid had oblivious growth-enhancing effects on Skeletonema costatum, as for the combined effects of gibberellin and naphthyleneacetic acid, the best ratio was detected at 0.75:0.25mg/L.
