Abstract:Based on the engineering consulting enterprise as an example to illustrate the growth mechanism of knowledge stock on knowledge service enterprise. By grounded theory research method and the research framework of symbiosis theory, the study found that symbiosis is the chief reason for the growth of the knowledge stock in engineering consulting enterprise. In a symbiosis relationship, the core categories includes three main categories: symbiosis unit, symbiosis symbiotic interface and symbiotic environment, and a criterion for abundance information. Symbiosis unit includes three impact factors: qualitative parameters (hard power, soft power), as parameter (seniority, cooperation intention) and physical parameters (density, symbiosis symbiotic dimension); Symbiosis interface includes two impact factors: tangible and intangible interface; Symbiosis environment includes two factors: internal environment (organization motivation, enterprise atmosphere, self-gratification, organization internal support) and the external environment (external). In a symbiosis relationship, the above factors interaction, eventually lead to the behavior process of the symbiosis (knowledge sharing) and symbiosis behavior results (knowledge stock).