During the seventh five-year plan of agricultural exploitation, the test area of Yucheng, Huang-Huan-Hai Plain, succeeded in popularizing the system of fish pond-plateform fields.In order to tap potentiality of the system and find out its best pattern, this paper analyzes heat content in different depths of fish pond under the condition of fishery environment and, therefore, concludes that it is suitable for water depth to be kept between 1.5 and 2.0 meters in ac-cordanic with climate of this area.