We have been developing wearable finger motion sensors such as an electroactive polymer sensor to measures the finger joint angle, and ring-type fingertip force sensor. The former is a simple structure that covers a finger joint with the electroactive polymer film that induces voltage by bending deformation. The latter is a novel method to estimate fingertip force from tendon tension using the relationship between fingertip force and tendon tension. Because these sensors are invented not to obstruct the tactile sensation and human nature motion, they are expected to be applied in various fields such as rehabilitation.