This paper dealt with single machine which had declining health index. It introduced recursion decline factor and failure rate ascending factor to build its imperfect maintenance model. By considering preventive maintenance (PM) and job scheduling, the PM model was expanded with order delay cost, while minimum interrupt cost was proposed together with minimum maxim tardiness and minimum total tardiness to model multi-objective job scheduling. The results of a numerical example indicate that this integrated model of PM and job scheduling is valid for planning comprehensive and optimal PM intervals and job schedules.