Purpose：We have investigated to analysis biomechanics for pinch strength due to elbow flexion degree. Methods：Pinch strength was measured by Electro Dynamometer(G-100) using four elbow flexion degree ($0^{circ}$, $45^{circ}$, $90^{circ}$, $135^{circ}$). Results：In experimental results, we found that pinch strengths were 5.4kg($0^{circ}$), 4.8kg($45^{circ}$), 5.6kg($90^{circ}$) and 5.2kg($135^{circ}$), respectively. The Pinch strengths got maximum at $90^{circ}$ degree, minimum at $45^{circ}$ degree. We have calculated F1 values using $sum$T=0. As a result F1 values were 540N($0^{circ}$), 480N($45^{circ}$), 560N($90^{circ}$) and 520N($135^{circ}$), respectively. F1 values got maximum at $90^{circ}$ degree, minimum at $45^{circ}$ degree. Data curve line of $F_1$ values was increased in 45~90 section and decreased in 0~45, 90~135 sections, respectively. Conclusion：$F_1$ (Flexor digitorum superficialis and profundus) values were 10 times bigger than pinch strengths. Data curve line of $F_1$ values was similar to active length-tension curve in 45~90, 90~135 sections.