We are constructing the ASCA GIS source catalog from the ASCA public archive, mainly for extra-galactic sky. The large field of view and the low-background characteristics of the GIS make it suitable for a search for serendipitous sources in a wide energy band of 0.7-10 keV. Sources to be detected by the project will provide valuable information on the log N-log S relation over the entire sensitivity band, which has never been available before. About this project, also refer to Ishisaki et al. (1995), Ueda et al. (1997) and Takahashi et al. (1997). There is the SIS source catalog project, too (Gotthelf et al., 1996). These catalogs are going to appear on the WEB.