A field experiment was conducted in Crop Research Farm, Department of Agronomy, Sam Higginbottom University of Agriculture, Technology and Science, Prayagraj, (U.P), during the zaid season of 2022 with the objective to study the ‟Influence of sea weed extract (Kappaphycus alverzii) and Zinc on growth and yield of Blackgram (Vigna mungo L.)”. Pulses are an integral part of many diets across the globe and they have great potential to improve human health. Black gram crop grown in many parts of India. This crop is grown in the cropping systems as a mixed crop, catch crop, sequential crop besides growing as a sole crop under residual moisture conditions after the harvest of other summer crops under semi-irrigated and dry land conditions ,and the variety is shekar 2. The soil in the experimental plot was sandy loam in texture, pH (6.9), low in organic carbon (0.112%), available N(278.93 kg ha-1), available P (10.80 kg ha-1) and available K (206.4 kg ha-1).The layout of the experiment was done in a Randomized block design with nine treatments which is replicated thrice. The 3 levels of concentration of sea weed extract (Kappaphycus alverzii) (2%, 3%, 4%) foliar application and three levels of zinc (15,20,25 kg ha-1) soil application.Growth and yield parameters namely plant height, dry weight, pods plant-1, number of seeds pod-1, test weight, seed yield, Stover yield, harvest index were collected from this experiment. Results revealed that significantly higher plant height (24.2cm), dry weight (4.9), pods/plant (21.2), seeds/pod (5.7), seed yield (637.0 kg ha-1), Stover yield (873 kg ha-1) were recorded with treatment combination of 4%K sap + ZnSO4 25 kg ha-1 (treatment 9). Maximum gross return (82819.00 INR/ha), net returns (55880.00 INR/ha), and benefit cost (2.07) were obtained highest in the treatment combination of 4%K sap + ZnSO4 25 kg ha-1 (treatment 9).