Software process supporting environment (PSE) is a kind of computer system that supports meta-process of software process. PSE controls and guides real-world software development process by enacting a pre-defined software process model (SPM). The way SPM uses to control real-word process can be categorized into two groups: proactive and reactive. The proactive way cannot support software process evolution well, so more and more people pay attention to the reactive way. A kind of reactive SPM and the graphic software process modeling language which is used to define it are presented. At the same time, for each model which is defined with this language, a method is proposed to express the dynamic semantics of its behavior view with the temporal logic language XYZ/E. This provides a rigorous dynamic semantics for the model and a formal basis for its enactment and analysis.