There are a lot of differences between the open source software development approaches and the traditional software engineering methods. If commercial organizations want to join the open source community, they must make some adjustments in their own original software development approach and business model. In this case, an urgent problem needs to be solved immediately is what involvement model the commercial organizations should adopt to achieve their goals of joining the open source community. This paper first collects project text data from the Internet as a basis for qualitative analysis using snowball-sampling collection mechanisms. Then, based on the classical grounded theory, it summarizes different commercial organizations' involvement model in open source projects through filtering and analyzing these data. Finally, the study extracts four kinds of general involvement model which can provide decision supports and experience references to those commercial organizations who want to join the open source software projects.