We demonstrate experimentally a high-Q one-dimensional photonic crystal cavity in a widely-used 450 × 220 nm single mode silicon ridge waveguide.Transmission spectrum measurement is performed by using the vertical fiber-grating coupling characterization method.The Q factor up to 2.6 × 104 is found by fitting the line shape of the transmission spectrum,and the normalized transmission of nearly 20％ is achieved.Three-dimensional finite difference time domain calculations show that the modal volume of the fundamental mode is 1.1(A/n)3.With the standard silicon waveguide width,the demonstrated 1D PhC cavity may be used as a building block for integrated photonic circuits and on-chip sensing applications.