Abstract: Open innovation paradigm has been distinguished into two dimensions: inbound open innovation and outbound open innovation. The rule-based system of inbound open innovation has been mainly researched in this study. After reviewing previous researches in terms of knowledge decision making theories of information system, this study establishes a four-dimensional decision mode of inbound open innovation and introduces an identification method of inbound open innovation paradigm based on Variable Precision Rough Sets (VPRS). With respect to data analysis, this study chooses the software ROSETTA system. Via completing, discretizing, reducing, generating rules and filtering, the rule-based system is built and testified by the testing samples.