128×128 element GaAs microlenses array is fabricated by a new method, named curvature inversion method. Scanning electron microscope (SEM) shows that microlenses have distinct spherical and concave contour, and surface stylus measurement shows that the concave microlenses array has smooth surface and its elements are of same size. For the concave microlenses array, the depth of concave spherical surface is 1.268 μm, the focal length is -352.04 μm.