Carbon dioxide sequestration by microalgae is receiving increased attention in alternative the impact of increasing CO2 in the atmosphere. Two microalgae viz., Scenedesmus and Chlorococcum were selected for this study. Nitrogen sources (Urea and ammonium nitrate) and carbon source (glucose and mannose) in different concentrations (0.02, 0.04, and 0.06%) were supplemented to Bristol medium and parameters such as Chlorophyll, Nitrogen, Carbon, and CO2 fixation were determined. Chlorococcum treated with different nitrogen sources showed a maximum amount of chlorophyll in 0.02% of urea. Maximum growth was also observed in 0.02% urea in Scenedesmus and Chlorococcum. In case of treatment with carbon sources maximum growth rate of Scenedesmus was recorded in 0.02% mannose whereas in Chlorococcum it was at 0.06% ammonium nitrate. Maximum nitrogen content obtained in Chlorococcum with 0.04% of mannose and Scenedesmus at 0.04% of glucose. The maximum amount of CO2 fixation rate was recorded in Scenedesmus and Chlorococcum at 0.2% urea concentration. Finally the result indicated that Scenedesmus sp. could be used for CO2 mitigation. Further urea and glucose in the media positively influence growth and CO2 fixation rate of micro algae.