Abstract: By the aid of optical engineering software ZEMAX, a five mega pixel mobile phone camera lens matched with one CMOS image sensor of 1.75m pixel size was designed, whose FOV is 60, F number is 2.8, half image height is 2.87mm, total length is 6mm and structure is 3P1G. Aspheric plastic was used for the first, third and fourth lenses. Sphere glass was used for the second lens. Transverse aberration of all the FOVs is less than 20m, RMS radius are less than Airy disk, and MTFs of most FOVs at half the Nyquist frequency (285lp/mm)of CMOS are greater than 0.6. This lens assembly has an excellent imaging performance.