Abstract: By employing survival analysis method on a large sample of invention patents from 211 project universities, this study constructs likelihood curve of patent assignment based on patent life cycle. The result shows that assignment likelihood of university patents first increases and reaches the peak five years after the patent application date, then decreasing over time. The study delves into the role of the university technology transfer office in university patent assignment process and the differential effects it might exert. Results of accelerated time models suggest that in general, the establishment of university technology transfer office does not have a significant effect on patent assignment speed. However, the existence of technology transfer office amplifies the negative relationship between the patent geographic protection scope, the number of inventors and the time needed for patent assignment, while it weakens the negative effect of inventors’ prior experience on assignment time. The study extends the understanding of university patent assignment process from a micro perspective and provides theoretical implications for improving the efficiency of university technology transfer offices.