Currently, many land observation satellites can be used in order to monitor natural environment. JAXA has a plan to launch new satellite GCOM-C1. SGLI is mounted on GCOM-C1, which can observe 380-12000nm spectral range in 250m sampling distance and 1150km swath. A mixed pixel analysis is a very important issue for an accurate environmental monitoring. Therefore, required accuracy of geometric transformation for GCOM-C1/SGLI should be understood. In this study, Landsat/OLI was used as reference data for geometric transform. The accuracy of superposing OLI on MODIS was evaluated by using simulated MODIS data. MODIS has a same ground sampling distance with SGLI. As the results, 1/5 pixel accuracy is required for mixed pixel analysis. Finally, Mixed pixel analysis was carried out real Landsat OLI and MODIS. The positional error of MODIS showed around 40-60m. The root mean square error between OLI and MODIS showed 12.6 (W/m2/sr/μm). It was bigger than simulation results. The reason might be come from transit time difference of satellite.