On the densely populated island of Java in Indonesia, the area of severely eroded upland is increasing at the rate of 1-2 percent per annum and now totals around 2 million hectares (ha), approximately one third of Java's cultivated uplands. Average population density in these areas is 600-700 people per sq km, although it may fall to 400-550 per sq km in severely degraded upper watersheds. With holdings averaging 0.4 ha or less, with up to 20-25 percent of the population being landless in some areas, and with yields for upland rice and corn averaging 0.9-2.5 tons/ha, the general pattern is one of poor, predominantly subsistence households seeking to increase their immediate basic food production by using cropping systems that result in high soil-erosion levels from their rainfed lands. In addition, significant erosion problems are caused by absentee and better-off farm owners cultivating highly profitable but erosive crops, such as vegetables, and by the failure to police state-owned tree plantations properly, particularly in preventing illegal fuelwood collection and agricultural conversion (Barbier 1987; Roche 1987; World Bank 1987b, 1988). This paper is concerned with the incentives for upland farmers on Java to adopt soil conservation as a means to control erosion and improve long-term land productivity and agricultural growth. The paper reviews the soil conservation packages currently offered to upland farmers and the factors influencing their adoption, as observed by existing farm-level studies. The appendix contains a model characterizing this behavior. As expected, farming households in Java are economically rational in their response to their environment, both physical and economic. Land tenure arrangements, soil characteristics, input and output prices, availability of offfarm employment, and discount rates all combine to influence acceptance or not of soil conservation. Government policies must take into account these variables if ffective programs are to be designed. This paper concentrates on the farmer's decision to invest in the control of soil loss and land degradation on privately owned and operated land in the Javan uplands. The additional erosion problems caused by the encroachment and conversion of open access and publicly owned forest lands for fuelwood, fodder, and shifting cultivation are not examined, as these appear to be of less importance (Donner 1987, 67-68). Thus, the following analysis is generally applicable to land degradation problems arising from sedentary upland cultivation in developing regions rather than those arising from shifting cultivation and open access degradation of forests (Lopez and Nicklitscheck 1988; Southgate and Pearce