With focusing on resource reserve estimation of porphyry iron deposits in the Middle and Lower Reaches of Yangtze River area, this study combined 3D Surpace with traditional research method and established 3D models for orebodies, dykes and gangue minerals based on collecting and integrating a variety of geological data. Based on national standards and the traditional methods of reliability classification to indentify types of resource reserves, 3D reserve estimation of porphyry iron deposits was conducted using a domain constrainted model. The results suggest that the latter can completely meet the requirements of related national standards for resources reserve estimation and can serve for submission of geological exploration reports.