Irrigation is main factor for agricultural production. Our aim is to increase agricultural yield by increasing area under irrigation. It is very important to see that more water available for irrigation is completely used as far as possible to avoid water loss during conveyance through canal. Seepage loss is major water loss during transit. Main purpose of this paper is to calculate seepage from earthen canal & apply appropriate lining material on canal to prevent this loss. Inflow-Outflow is the best method to measure seepage loss accurately. Study was undertaken at reach no 2 from mile 19/4 to mile 42 of Nira Left Bank Canal off taking from Vir dam. According to study, it was found that 2.55 TMC/34.96km water is lost due to seepage. Comparative study of canal lining material has been proposed for NLBC to save seepage losses. Concrete canvas-8mm is the most effective & long life lining material, which saves 95-100% water lost by seepage alone as compare to cement concrete.