The purpose of this study is to investigate the physicochemcal properties of the cowpea crude and refined starch and to present the basic data for physicochemical factor which gives the properties of Mook to cowpea starch gel. Water binding capacity of crude starch was 235.1% and that of refined starch was 186.0%. The pattern of change in swelling power and solubility for increasing temperature started to increase at 60℃ and increased rapidly from 70℃, for both of crude and refined starch. The optical transmittance of 0.2% crude and refined starch suspensions were increased from 65℃ and showed rapid increasement during 68∼80℃, and their curves showed two-stage processes. The gelatinization pattern for 6% crude and refined starch suspensions were investigated by the Brabender amylograph. The curves showed the pasting temperature of 72.0℃ and 72.1℃, peak height of 1130 B.U.(88.0℃) and 970 B.U.(83.5℃) for crude and refined starch, respectively, and both showed high viscosities when cooling. Blue values for crude and refined starch were 0.369 and 0.376 respectively. Alkali number of crude and refined starch were 7.77 and 7.34, and reducing values were 3.60 and 2.10, respectively. Amylose content of cowpea starch was 33.7%. Periodate oxidation of the starch fractions resulted that amylose had the average molecular weight of 23590, degree of polymerization of 146 and amylopectin had the degree of branching of 3.42, glucose unit per segment of 29.