The present invention relates to a solar cell having quantum dot nanowire array and the fabrication method thereof. The solar cell according to the present invention includes quantum dot nanowire array with a heterostructure including matrix and semiconductor quantum dots, and p-type and n-type semiconductor and electrodes each contacting the quantum dot nanowires. With the solar cell according to the present invention, the band gap energy of the semiconductor quantum dot can be easily controlled, the semiconductor quantum dots having different sizes are provided in the quantum dot nanowire so that the photoelectric conversion can be performed in the wide spectrum from visible rays to infrared rays, the quantum dot is embedded in the high density quantum dot nanowire array so that light absorption can be maximized, and the quantum dot nanowire contact p-type and n-type semiconductor over a wide area, conduction efficiency of electrons and holes can be improved.