Increase in the scarcity of the fossil fuels, prices and global warming have generated an interest in developing alternate fuel for engine. Technologies now focusing on development of plant based fuel, plant oils and plant fats as alternative fuel. The present work deals with finding the better compression ratio for the honne oil diesel blend fueled C.I engine at variable load and constant speed operation. In order to find out optimum compression ratio, experiments are carried out on a single cylinder four stroke variable compression ratio diesel engine. Engine performance tests are carried out at different compression ratio values. The optimum compression ratio that gives better engine performance is found from the experimental results. Using experimental data Artificial Neural Network (ANN) model was developed and the values were predicted using ANN. Finally the predicted values were validated with the experimentally.