The mechanical properties of the anterior cruciate ligament (ACL) were investigated. The method of a versatile clamp was designed to holding the femur-ACL-tibia complex (FATC). Twelve porcine FACT specimens were tested at angle 30° and the parallel direction of the ACL. The static tensile and stress relaxation tests were performed with an Instron-type universal testing machine. Differences in stress-strain behavior at the two (slow and fast) deformation rates. The ACL AM (anteromedial) bundle exhibited significant distribution of the deformation at the two deformation rates. Good agreement is obtained using Y. C. Fung's QLV (quasi-linear viscoelastic) theory relationship between theoretical and experimental data.