Abstract. This article described about the effect of surface modification on newly identified natural fiber in the name of veldt grape stem fibers (cissus quadrangularis) were extracted and investicated. The extracted veldt grape stem fibers (VSF) is treated with alkali chemical with various concentrations like 5%, 10 % and 15 % for a constant soaking time of 60 min. The true cross sectional areas were measured for treated and untreated fibers using electron microscope and image J software. The tensile properties of chemically treated fiber were studied using Instron universal testing machine and found the better tensile properties on 10% chemical concentrations, which considered as optimum case of alkali treatment. The fibers density, chemical compositions like cellulose, lignin, wax, moisture and ash content also studied for optimal case based on tensile strength. The characterization of optimally NaOH treated fibers was analysed by using of XRD technique.