Abstract: In this paper the influence of the limb-darkening effects on stellar angular diameter measurement were studied. It shows that both UD and linear results underestimate the value of angular diameter; the difference is larger at stronger limb-darkening effects (c0 - 0), the largest difference among UD, linear result and quadric approach are 25.5%, 12.6% respectively. While their differences can be ignored when co tended to one. However, the difference between new and old linear approach seems small, it thinks that the quadric limb-darkening effects should be considered in the measurement of the stellar angular diameter.