In the southern part of China over 70% of the cultivated area is under rice. A tremendous amount of water is used for the rice fields under the traditional irrigation method, termed 'shallow flooding irrigation1. Since the 1980s, in some provinces in south China, a new irrigation technique for rice, termed 'water-saving irrigation', has been advanced. In recent years this new technique has become widespread. The basic feature of this new irrigation technique is that there is no water layer above the soil surface in rice fields during the growing season of rice after the stage of recovering. This technique not only saves water and increases the rice yields, it also: reduces soil and water pollution; improves soil aeration; improves the field's microclimatic condition; reduces rice diseases and insect pests; and improves the regional water balance. This paper discusses the details of the water-saving irrigation technique for rice, and its potential environmental impact in south China.