As a real- time monitoring of human body movement and health, flexible wearable electronic devices have attracted wide attention. In order to develop the strain sensors of polyamide filaments/spandex yarn, polyamide filaments/spandex covered yarn was manufactured by a twister using spandex as core and polyamide filaments as sheath. Conductive polyamide/spandex covered yarn was made by chemical silver-plate and carbon black coating. Experiment results show that the linear resistance of the conductive covered yarn with twist 50 T/10 cm is 1.97 /cm. The resistance change ratio of the conductive yarn with twist 50 T/10 cm is stable and the repetitive stability error is smaller after 20 stretching-recovery cycles. As a strain sensor, the conductive yarn with twist 50 T/10 cm could better sense the motion signals of finger bending and wrist bending.