Purpose: The purposes of this study were to establish the concurrent validity of the universal goniometer and electronic inclinometer for ankle joint of motion, and to determine the inter-tester and the intra-tester reliability of these two instruments. Methods: Subjects were instructed 25 healthy subjects. Ankle range of motion was measured on two separate occasions 2 or 3 days by two physical therapists. Ankle dorsiflexion and plantarflexion was by using an universal goniometer and an electronic inclinometer. Results: The Pearson product-moment correlation between the two instruments was 0.78~0.80. The ICCs for inter-tester reliability ranged from 0.63 to 0.73 for universal goniometer and ranged from 0.81 to 0.88 for electric inclinometer. The ICCs for intra-tester reliability showed a wide variation(ICC=0.61 to 0.86). Conclusion: These findings indicate that the two instruments are reliable instruments for measuring ankle joint range of motion. The results also indicate that the two instruments can be used interchangeably for measuring ankle motions.