In order to save the cost of software rejuvenation, improve the reliability of software and ad-vance the applicability of anti-aging, the fine-grained software anti-aging was executed in distributed system. The establishment of rational rejuvenation levels, searching of direct coupling modules and e- duction of restart chains on different levels are the keys of fine-grained software rejuvenation policy. Based on coupling relation of controlling, calling and data inquiring between the modules on different levels of distributed system. The system restartable level standard was set down, a method to search the direct coupling modules and restartable set of modules was put forward, the restartable priority lev?el was defined, the constructional rule of the restartable chains on different levels was obtained, and then a policy of the retartable implement was established; and the four-level nested anti-aging retartable model was established by comprehended stochastic Petri net and determinative finite automaton. To support the anti-aging of software with fine rejuvenation granularity in distributed system.