To simulate the effects of pitting corrosion morphologies on the mechanical behavior of steel bars, tensile static and fatigue tests were conducted on one hundred steel bars. Specimens of four notch shapes, six notch sizes were chosen for test. Quantitative relationships of the yield and the ultimate load under different notch depths were obtained based on the tensile test. The stress concentration coefficients under various notches were also compared. The effect of notch shape and notch size on the fatigue life of steel bars was observed based on the fatigue tensile test. The equations for stress range fatigue life notch depth were also established. Following that, the stress distribution near the notches was analyzed, and corrosion pit induced performance degradation of steel bars was explained by establishing an accurate three dimensional finite element model. The results show that triangular notch has the maximum stress concentration coefficient under a same notch depth, followed by length variable triangle, radial ellipse and axial ellipse shaped notch. The magnitude of stress concentration at the notch location increased with increasing stress level and notch depth. A linear relationship is observed for the stress range and fatigue life of the notched steel bars in logarithmic scale. The triangle and length variable triangle corrosion pits have a relatively higher stress concentration gradient and will lead the steel to enter a plastic deformation stage firstly until failure.