Root and tuber crops consisting of cassava, sweet potato, potato, taro and others root and tubers have the important roles as the source of food, nutrition and cash income for many farmers in Indonesia. These crops also as a source of carbohydrates beside rice, corn, cereals, wheat etc. Root and tuber crops are the second most important group of crop plants after the cereals. The government of Indonesia accelerate food diversification based on local food resources, especially facing the climate change. The objective of this study was to estimate the role of root and tuber crops on food diversification and to estimate the household root and tuber crops demand in East Java Indonesia. The research used SUSENAS (Indonesian National Socio-Economic Survey) 2020 data with 31.990 household respondents in East Java Indonesia. Demand for food was estimated by AIDS (Almost Ideal Demand System) model. The results show that the average consumption for root and tuber crops was 0,69 kg/household/week (11,23% from carbohydrates foods), whereas rice consumption amount 4,86 kg/household/week (79,68 %), maize amount 0,25 kg/household/week (4,13%) and cereals amount 0,3 kg/household/week (4,96%). The expenditure elasticity of root and tuber crops was 1,36, while the expenditure elasticity of rice amount 0,78 (normal food), maize (1,41) and cereals (1,27). The expenditure elasticity more than 1 means that root and tuber crops as a superior food, also for maize and cereals. People no longer considers that root and tuber crops to be an inferior food. The root and tuber crops consumptions have the highest proportion after rice. It can be mean that root and tuber crops have the important role on food diversification in East Java Indonesia. Facing the climate change, root and tuber crops development be a right decision, moreover, root and tuber crops can be planted on dry land which is still widely available in Indonesia.