Three runoff models based on the model proposed by Kadoya and Nagai are developed as a clue for improving the reproducibility of hydrograph for peak flood duration. The first model is composed of four series storage tanks. The first upper tank is divided into upper and lower tanks. And the effect of depression storage is included in the first upper tank. The structure of lower tank is the same as the Kadoya and Nagai's model. The first upper tank is divided into two parts in the ratio of β in left to 1-β in right，too. In the left part，only the surface runoff occurs due to the input of rain water. In the right part, both surface and prompt subsurface runoff occur. The second modelis arranged the first model in parallel for evaluating the effect of storage in the runoff process of the basin slope. The third model is composed by kinematic wave runoff model in the upper zone and the lower part of the storage model proposed by Kadoya and Nagai in the lower zone. Runoff simulation for three runoff models is examined and it is pointed out that the last is the best model from a physical view point of runoff. The reservation curve of rain water is calculated from the value of effective rainfall estimated by the last model. And the characteristics of reserved rain water at small or mild intensity rainfall is shown well by the curve.