A projection lens regulator for a projection television includes a base, a barrel and an immobilizing hoop. The base has an annular wall, a slope guide slot at the annular wall, and a resilient flexible sheet defined by a pair of incisions at an upper side of the annular wall. The barrel is fitted inside the annular wall of the base and has an annular wall and a slope guide rib at an outer surface of the annular wall of the barrel. The slope guide rib is movably received in the slope guide slot of the base. The immobilizing hoop has an annular wall fitted on the base, and an arched convexity, which is formed at an inner surface of the annular wall thereof, corresponding in position to the flexible sheet of the base.