Two-dimensional(2D)slab photonic crystal waveguides(PCWGs)on silicon-on-insulator(SOI)wafer were designed and fabricated.Full photonic band gap,band gap guided mode,and index guided mode were observed by measuring the transmission spectra.Mini-stop-bands in the PCWG were simulated with different structure parameters.Coupling characteristics of PCWG were investigated theoretically consid- ering the imperfections during the fabrication process.It was found that suppressing power reservation effect can realize both short coupling length and high coupling efficiency. Two-dimensional (2D) slab photonic crystal waveguides (PCWGs) on silicon-on-insulator (SOI) wafer were designed and fabricated. Full photon band gap, band gap guided mode, and index guided mode were observed by measuring the transmission spectra. Mini-stop-bands in the PCWG were simulated with different structure parameters. Coupling characteristics of PCWG were investigated theoretically consid- ering the imperfections during the fabrication process. It was found that damping power reservation effect both realize both short coupling length and high coupling efficiency .