The method for manufacturing a CMOS image sensor is employed to prevent bridge phenomenon between adjacent microlenses by employing openings between the microlenses. The method includes the steps of: preparing a semiconductor substrate including isolation regions and photodiodes therein obtained by a predetermined process; forming an interlayer dielectric (ILD), metal interconnections and a passivation layer formed on the semiconductor substrate in sequence; forming a color filter array having a plurality of color filters on the passivation layer; forming an over-coating layer (OCL) on the color filter array by using a positive photoresist or a negative photoresist; forming openings in the OCL by patterning the OCL by using a predetermined mask; and forming dome-typed microlenses on a patterned OCL.