PROBLEM TO BE SOLVED: To provide a plant activator in which a price is cheaper than that of a conventional one, further a growth rate can be made larger than that of a conventional one, and a plant that is also excellent in a quality can be grown and a production method of the same.SOLUTION: A plant activator includes a solution that is obtained by that aquatic products such as a seafood are performed by decomposition treatment by high pressure hot water (subcritical water) as a main component. A production method of the plant activator is characterized in that the aquatic products such the seafood are performed by decomposition treatment by high pressure hot water (subcritical water) of at most 250°C temperature.COPYRIGHT: (C)2014,JPO&INPIT【課題】従来よりも安価であり、さらに、従来よりも成長速度を大きくすることが可能であるとともに、品質においても優れた植物を生育可能な植物活性化剤及びその製造方法を提供することを目的とすること。【解決手段】魚介類などの水産物を高圧熱水(亜臨界水)により分解処理して得られた溶液を主成分とする植物活性化剤。250℃以下の温度の高圧熱水(亜臨界水)により魚介類などの水産物を分解処理することを特徴とする植物活性化剤の製造方法。【選択図】図1