A dynamic model of skeletal muscle is developed to describe its activation kinetics and contraction dynamics based on the collective working mechanism of myosin II motors with a statistical mechanics method.According to the structure of sarcomeres arranged in series and in parallel,the mechanical properties of skeletal muscle are studied.This model reveals the relations between action potential and muscle characteristics.It is shown that calcium concentration in sarcoplasmic(SP) increases linearly with the increasing stimulation frequency and gradually reaches saturation.Active force and contraction velocity follow the trend of calcium concentration and reach a peak value at the maximum stimulation frequency.Contraction velocity is inversely proportional to the load while the contraction power increases to maximum and then reduces to zero with the increasing load.These properties are consistent with published physiological experimental results of skeletal muscle. A dynamic model of skeletal muscle is developed to describe its activation kinetics and contraction dynamics based on the collective working mechanism of myosin II motors with a statistical mechanics method. According to the structure of sarcomeres arranged in series and in parallel, the mechanical properties of skeletal muscle are studied. This model reveals the relations between action potential and muscle characteristics. It is shown that calcium concentration in sarcoplasmic (SP) increases linearly with the increasing stimulation frequency and gradually reaching saturation. Active and contraction velocity follow the trend of calcium concentration and reach a peak value at the maximum stimulation frequency. Contraction velocity is inversely proportional to the load while the contraction power increases to maximum and then reduces to zero with the increasing load .sese properties are consistent with published physiological experimental results of skeletal muscle.