Scientific data sharing is a complex and systematic project. Although there have conducted many researches and acquired fruitful achievement of data sharing in recent years, the progress of data sharing has not reached the ideal state as governors and scientists expected. For reasons, besides the obstacle from personal economic benefits and intellectual property rights protection, correlated laws and policies insufficient, and software platform imperfect, one important issue is people always ignore the quality of data sharing service. Good data sharing service quality means users can easily find out, quickly access or download data resources online and correctly use them. In this paper, based on more than 6 years research and practice of Earth System Scientific Data Sharing Network, one of National Infrastructure and Facility Development Environment Building for Science and Technology Industries Program of China, first of all authors analyze the signification of data sharing service quality and then point out the key problems of data sharing service provided by data centers and networks of Chinese scientific data sharing project. Finally a new data sharing service quality control method, metadata-data services-data documents integrative binding, is put forward and discussed in detail.