Under a tropical environment water is the most important factor in lowland rice cropping. By developing new irrigation systems lowland rice areas in Indonesia have been expanded from about 1.2 million ha in 1860 to 3.3 million ha in 1935 and 5.1 million ha in 1955. By 1980 the extent of lowland rice areas included 4.0 million ha with irrigation and 2.2 million under rainfed conditions. Since 1969 major programs have been implemented to increase rice production by intensifying cultivation and expanding the area planted to rice. Rice double cropping, using early-maturing varieties followed by an upland crop, is recommended in irrigated lowland areas. The average cropping intensity index of the whole lowland rice by 1982 was estimated to be 1.3. Building irrigation systems and the development of earlymaturing non-photosensitive varieties are two important aspects for intensifying rice cropping. Major constraints in intensive rice-producing areas, however are pests and diseases and the possible decline of soil productivity. The current research program, strategies and activities to increase, stabilize and sustain high rice yields are discussed.