Social Information Science (or Social Informatics) is a new and interdiscipline branch subject in China. This paper probe the emergence and the research outline of social information science. 1. The proposal of the social information science. We set up the research from an extension from the theoretical informatics to the concrete informatics; a internal bond of integrating various subjects in humane and social sciences; an intersection and mutual permeation between the social science and the natural science; a the intersection and (...) interaction among humane and social sciences, modern information science and information technology; a strengthening to the research into Social Epistemology. Ⅱ. On the concept of social information. Social information directly is different with selfexistent and natural information, and more related to human’s autonomous creative activities, to society’s culture inheritance, to social value, to human’s spiritual interaction and to human’s emotions. Ⅲ.On the theoretical orientation of the social information science. Social Information Science is a concrete branch of informatics, a generation of sub-disciplines of social information, a kind of traversing and comprehensive research on individual social science from the angle of information, a kind of exchange and interaction between social theoretical research and the modern information technology. Ⅳ. The research focus of the social information science. The paper lists 10 main focus in the research of social information science. Ⅴ.The system and frame of the social information science. In general, there should be four levels of researches if the social information science is to be viewed as a relatively independent subject: the philosophical level, the scientific theoretical level, concrete apply level, social information technology and methods. (shrink)