In this paper, we present a cost effective parallel-branch spiral inductor with the enhanced quality factor and the resonance frequency. This structure is designed to improve the quality factor, but different from other fully stacked spiral inductors. The parallel-branch effect is increased by overlapping the first metal below the second metal with same direction. Measurement result shows an increased quality factor of 12 % improvement. Also, we show an octagonal parallel-branch inductor which reduces the parasitic capacitances for higher frequency applications.