The demonstrations on lentil and blackgram were conducted by Coochbehar KVK during the period 2005-06,2006-07, 2007-08 and 2008-09 in four villages ( Khagribari, Bhogdabri, Moyamari and Barashakdal ) of three blocks viz. Coochbehar-I, Coochbehar- II and Dinhata-II. During these four years (2005-06 to 2008-09), 8.2 hectares under blackgram and 11.2 hectares under lentil were demonstrated with improved management practices using improved varieties. Altogether, 68 and 99 farmers were closely associated with blackgram and lentil demonstrations, respectively.  During four consecutive years of demonstration it was observed that the demonstration plots were always the higher yielder as compared to the plots maintained by the farmers on their own. On an average, there was an appreciable increase in yield level ( 58.45% in blakgram and 40.65% in lentil) under demonstration plots. The average demonstration yield of blackgram was varying between 8.75 to 9.50 q/ha; while in case of lentil, the demonstration yields ranged between 7.30 to 9.20 q/ha. As far as production economics was concerned, the B-C ratio varied between 1.98-2.33 and 2.76-3.10 in blackgram and lentil, respectively. The B-C ratio indicated the feasibility of the demonstration in farmer’s field.