This paper presents an improved 4-stage on-chip open loop resonator band pass filter (OLR-BPF) for 60 GHz millimeter-wave applications in 0.18 μm CMOS technology. The proposed on-chip BPF employs the folded open loop structure on patterned ground shields in first two stage and open-loop resonator in last two stages to improve the selectivity. By comparison between the electromagnetic (EM) simulations and measurement results, the proposed BPF has the center frequency of 57 GHz, insertion loss 3.06 dB, band width 12 GHz, return loss is less than 30 dB, and chip size 0.73 μm2 (including bonding pads).