For developing countries, agricultural sector is important because it creates jobs and contributes in food security. With a large number of members, the WTO negotiations are often held through coalition participation. Indonesia joined three coalitions regarding agricultural issue, namely Cairns Group, G-33 and G-20. But, Indonesia's membership in Cairns Group is considered contrary to the interests of Indonesia because Indonesia is trying for market closure due to flood of imports, while Cairns Group wants the expansion of market access. This research uses neoliberalism perspective, to analyze the results of liberalization on agricultural markets as the implementation of WTO negotiations. The concepts used are international trade, trade barriers, national interest, coalition and multilateral diplomacy. Research used secondary data quantitative and qualitative data to deepen the analysis about Indonesia agricultural sector after liberalization applied. The research analysis focus on the impact of agricultural liberalization in Indonesia. Agricultural liberalization resulted in decreasing productivity and production of food crops commodity which lead to Indonesia has increasing import which impact the food security and high import dependence. Therefore, Indonesia is struggling with Special Products and Special Safeguard Mechanism concepts in effort to protect domestic market. In contrast, plantation commodity is export increasing, so Indonesia's membership in Cairns Group is expected to help plantation commodity evermore, while with G-33 Indonesia is aiming to protect food crops farmers.