This paper proposes the CPW-fed spiral resonators with Hilbert slot configuration in defect ground structure (DGS) for a bandpass filter (BPF). For comparison, three CPW-fed spiral filters are fabricated and measured. To obtain low insertion loss (–0.81dB/–0.87dB), high out-of-band rejection level (–38.22dB/–42.74dB) and wider bandwidth (22.8%/36.3%) of 2.4/5.8GHz frequency responses, the CPW-fed slot spiral resonators with cross line are applied for WLAN dual-band systems. The design procedure for dual-band filter is presented. The proposed filter is successfully simulated and measured to obtain the agreeable frequency responses.