A worktable for a circular saw includes a rotatable table defining a cutting groove, two movable fences arranged on the rotatable table at two opposed sides relative to the cutting groove, and a connection member connected between the two movable fences. The connection member has an arc-shaped locating groove and is adapted for engagement with a guide member of the rotatable table so that when the rotatable table is rotated, the guide member engages and applies a force to the wall of the arc-shaped locating groove, causing the two movable fences to be moved relative to the cutting groove, and therefore the two movable fences are maintained spaced away from the cutting groove at a distance without interfering with the operation of the saw blade.