. Adiyoga, W., T. A. Soetiarso, and M. Ameriana. 2008. Component Interactions in Crop-livestock System in West Java Highland Ecosystem. This study was carried out in West Java highland areas (Lembang – Cibodas and Suntenjaya village, Pangalengan-Pulosari and Margamulya village, and Ciwidey – Lebakmuncang and Panundaan village) from June to October 2004. The objective of this study was to examine the component interactions of crop-livestock system in highland ecosystem. Respondents surveyed were those who grew vegetables and raised livestock simultaneously. Number of respondents selected were as follows: Lembang 40 respondents, Pangalengan 45 respondents, and Ciwidey 44 respondents. The results showed that crop livestock system (CLS) in West Java highland can be classified as diversified mixed farming systems, not integrated, consist of components such as crops and livestock that co-exist rather independently from each other (minimum interactions). In this case the mixing of vegetable crops and dairy-cows primarily serves to minimize risk and not to recycle resources. Nutrient flows tend to be linear, since the activity of resource-recycling is not significant. Minimum interactions between components were also reflected from zero contribution of labor from dairy-cow subsystem to the total labor requirement for vegetable cultivation; 0-25% contribution of manure from dairy-cow subsystem to the total organic fertilizer requirement for vegetable cultivation, and 0-10% contribution of crop wastes or by-products from vegetable farming to the total feed requirement for dairy-cows farming. Regarding resource utilization, there was high competition in labor-use, especially family labor, between vegetable and dairy-cows farming. Positive impacts of CLS perceived to be significant were the use of leys containing grasses and legumes to reduce erosion and use of manure to improve soil structure and fertility. Meanwhile, the negative impacts of CLS, such as pollution; environmental disruption and health hazards from disease and pest chemical control measures were beginning to be perceived as slightly significant and need more attention for finding the problem solution.