Drying characteristics of paddy (long grain variety PR-118 procured from PAU, Ludhiana) in an integrated dryer using single as well as combined heating source was studied at different air temperatures. The integrated dryer comprises three different air heating sources such as solar, biomass and electrical. Drying of paddy occurred in falling rate period. It was observed that duration of drying of paddy from 22 to 13 % moisture content (w.b.) was 5-9 h depending upon the source of energy used. In order to select a suitable drying curve, six thin layer-drying models (Newton, Page, Modified Page, Henderson and Pabis, Logarithmic and Wang and Singh) were fitted to the experimental moisture ratio data. Among the mathematical models investigated, Wang and Singh model best described the drying behaviour of paddy using solar, biomass and combined heating sources with highest coefficient of determination (r 2 ) values and least chi-square, χ 2 , mean bias error (MBE) and root mean square error (RMSE) values. However, Page model adequately described the drying behavior of paddy using electrical heating source.Keywords Paddy . Integrated paddy dryer . Drying models . Moisture ratio Paddy or rough rice (Oryza Sativa L.), the most widely grown food grain crop, is the staple food of over 3 billion people. World and Indian rough rice production in 2010 was 700 million tonnes and 143.9 million tonnes respectively (FAOSTAT 2010). Rice provides more calories per hectare than any other cereal crops. Its nutritional value is high among cereals and grains. Though the protein content of rice is less than that of wheat, the protein digestibility and biological value of rice protein are the highest among wheat and other cereals. After harvesting, paddy normally goes through two moisture treatments; one is drying that may be required for safe storage, and the other is water absorption in preparation for further processing. Quality deterioration takes place if fresh paddy is not immediately dried to safe moisture level. Drying reduces bulk quantity, thus, facilitates in transportation, handling and storage. Although sundrying is economical, mechanical drying speeds up the process, prevents losses, ensures use of safer drying temperatures and produces superior product compared to sun drying (Mudahar and Bains 1982). In view of high cost and non-renewable nature of the present conventional electrical energy source, different renewable energy sources such as solar and bio mass may be employed for paddy drying. The combining of conventional and non-conventional energy sources for paddy drying will be helpful for exploiting solar and bio mass sources as much as possible.The drying characteristics of food is a complex phenomenon and requires simple representations to predict