Abstract: When the plane tree was treated with deciduous agent in Autumn,the moisture content of the leaf blades declined, the chlorophyll content dropped,the electrolytic exosmotic rate increased and the activity of hydrogen peroxidase became weak. As result,the leaf blades were shriveled by degrees, the abscission layers formed acceleratively and over 95% of the leaf blades fell off within 30 days.All these showed that the deciduous agent of plane tree could destroy the integrality of the cell membrance,which might be closely related to reduction of activity hydrogen of the peroxidase, the great accumulation of the hydrogen peroxide and proxidation lipoid membrance of the leaf cell.

Key words: Sepia lycidas,  , temperature, hatching rate, larval growth.