Yield gap analysis of individual crops in a cropping system has been done to explore the opportunities for increasing crop production which may provide important information to the policy makers for augmenting food security. In this context, study has been undertaken in Terai Zone of India, specifically West Bengal. The cropping system predominantly in the area is Kharif Paddy-Potato-Jute. We used econometric models Multiple Regression Analysis, for identified the factor which is cause to yield gaps. The result shows that Yield gaps have been found for all crops as well as cropping pattern of farmers in various levels. Regression analysis reveals that various factors like participate family member in farming, family head of education, age of head, farm holding, contact with social office, manures, farm distance etc. remain the most significant ( p< 0.01; p<0.05; p<0.1 ) to influence the yield gap. This led to the conclusion that the yield gap could be deeply reduced by controlling local agronomic management and improving socioeconomic factors.