According to precipitation use and irrigation degree, the research to the semi-dryland agriculture was conducted. The paper emphatically discussed the questions of implication related with the semi-dryland agriculture, expounded the significance of the water deficit areas of North China, and gave the semi-dryland agricultural limited supplemental irrigation technology mode. Bssed on the characteristics of the water deficit areas in North China, the model and tactics of developing semi-dryland agriculture limited supplemental irrigation in different type areas were put forward.