Based on the CCD images, IIM data and DEM data of China’s lunar exploration project (Chang’E-I) and related processed and analytic results, an integrated study of regional geology of Sinus Iridum and its adjacent area was conducted, and a series of relevant researches and analyses were carried out, including analysis of impact craters and their extrusive and accumulative materials, division of stratigraphic and tectonic units and classification of rock types, integrated analysis of chronology and lunar evolution history. In consideration of crater’s shape features，quantity and preserving status of filling materials, the lunar impact craters can be divided into 7 types and 11 sub-types, and the accumulative materials of craters are divided into 6 types and 9 accumulative groups. According to the content and distribution of TiO2 and image characteristics, the basalts are divided into high-TiO2, medium-TiO2 and low-TiO2 basalts. Discussion was made on division of tectonic units and evolution features in the study area. The geological map of the Sinus Iridum Quadrangle (LQ-4) at a scale of 1:2.5 M was preliminarily compiled with the ArcGIS system, and the spatial database of the map was established. Related technical specification, procedure and method for lunar geological mapping have been worked out, so as to lay a foundation for the forthcoming geological mapping of the global Moon in China by using the data of Chang’E-II and also for comprehensive study and geological mapping of other celestial bodies in the future.