Pultruded FRP can be regarded as an orthotropic material due to its manufacturing process that pull-out fibers impregnated with polymeric resin, which is suitable to produce structural member with unlimited lengths of reinforced polymer structural shapes with a various shape of cross-section. However, fiber distribution in the cross-section is not uniform because of the characteristics of pultrusion process. Therefore, random fiber distribution causes the difference of the modulus of elasticity throughout the cross-section. In this paper, closed-form local buckling analysis is conducted on the pultruded FRP I-shape compression members. The mechanical properties used to analytical investigations are obtained from the coupon test. The coupon test specimens are taken from the pultruded FRP I-shape member. Moreover, the local buckling tests of pultruded FRP I-shape members are conducted and test results are compared with the analytical results.