Plastic is the one of the waste material which is increasing day by day where as the concrete is the construction material which is also using more day by day. As the plastic is harmful material for environment so to decrease the plastic material we are using the one of the most important material waste i.e pen waste in the place of fine aggregate. The replacement of waste with fine aggregates by different proportions for M20 grade of concrete is done (2%,4%,6%,8% &10%) and strength was increased with 4 % of waste.