Abstract: National geological survey is characterized by data-intensiveness, computing-intensiveness, distribution of resources, and heterogeneous information systems. As an innovative high performance computing environment and information services infrastructure, a grid can meet geological survey application requirements by its dynamic, distributed resources sharing and collaboration. Based on grid computing, national geological application grid（NGG）, a novel service-oriented architecture with seven levels from information acquirement, processing to application is proposed. To solve application problems some crucial technologies of NGG are discussed in detail, such as resource management, resource trading, service chain, etc. Moreover a new service chain model （named service/resource net） based on Petri net and graph theory is presented.