With the rapid development of knowledge economy and knowledge management, the measurement about knowledge is increasingly showing its importance. As the intangibility and complexity of knowledge characteristics, the issue of measurement about work knowledge and work knowledge intensity has become one of the management challenges, an important research topic, also management issue needed explored in the new century. In this paper, analysis of the knowledge natures and characteristics, research on measurement of knowledge and knowledge content are expected for solving the measurement of work knowledge content, assessment of knowledge work productivity and other issues of knowledge work.