Job burnout is a three-dimensional syndrome in response to chronic work-related stressors, including emotional exhaustion, depersonalization and reduced personal accomplishment. Over the past four decades, much effort has been devoted to understanding what job burnout is and why it happens. A host of studies have used the job demands-resources (JD-R) model as a theoretical framework to examine how different job characteristics influence job burnout. The main purpose of this three-wave longitudinal study is to investigate how changes in job demands (workload, emotional demands, work-family conflict) and resources (autonomy, social support, performance feedback, and opportunities to development) and burnout affect each other over time. Full-time employees working in three large Chinese companies were approached three times over a one-year period from June 2012 to June 2013. The final sample consists of 263 participants with an average age of 34.46 years and organizational tenure of 5.59 years, including 44% males and 56% females. The preliminary analysis shows that the attrition of participants is at random, thus it will not affect the validity of the results. Structural equation modeling analysis shows that the hypothesized model fits the data very well (=573.46，RMSEA=.043，CFI=.93，IFI=.93，TLI=.92). It can be concluded job demands positively affects and job resources negatively affects job burnout over time, which in turn leads to a further increase in job demands and decrease in job resources. In addition, Bootstrap analysis shows that all the specific mediation effects are significant as the confidence intervals do not contain zero. Our study has established a longitudinal link between changes in job-related characteristics and development of burnout. Burned out individuals are more likely to experience a “deteriorated work environment→increased burnout” cycle. This study enhances current knowledge about the development of burnout in several respects, and the findings have important implications for preventive interventions with regard to burnout. A comprehensive JD-R model based intervention strategy has been proposed.