A method of manufacturing a redistribution circuit structure is provided. First, a substrate is provided. The substrate has a plurality of pads and a passivation layer. The passivation layer has a plurality of first openings exposing a portion of each of the pads, respectively. A first patterned photoresist layer is formed on the passivation layer. The first patterned photoresist layer has a plurality of second openings exposing a portion of each of the pads. A plurality of first bumps is formed in the second openings, respectively. An under ball metal (UBM) material layer is formed over the substrate to cover the first patterned photoresist layer and the first bumps. A plurality of conductive lines is formed on the UBM material layer. The UBM material layer is patterned to form a plurality of UBM layers using the conductive lines as a mask.