It is reported that the anterior cruciate ligament (ACL) has a sensitive function that regulates proprioception. The partial or total rupture of ACL could reduce proprioception. In this study, we investigated whether the direction of joint motion has an affect on proprioceptive sensibility. Eight subjects (5 men and 3 women) who did not have any history of previous injury or surgery to either knee joint participated. Two kinds of tasks for knee joint position sense were examined using a specially made article to record target joint angles and to calculate reproduced angles after limb movement. Task A involved extension from a 30°flexed position and task B involved flexion from a totally extended position. The repositioning angle departed from target angle (15°) within one degree in each task. Mean real error indicated a tendency to underestimate reproduced joint angles in all tasks, although the magnitude of the error was small. Absolute error was around two degrees. No significant difference was found in repositioning angle, real error or absolute error between task A and task B. These data show that direction of joint motion does not affect knee joint position sense. It is suggested that joint direction can be chosen at will in the measurement of knee joint position sense. Further investigations may include measurements of ACL injured patients to clarify the influence of ACL mechanoreceptors by comparison with the present study as a control group.