Based on Job Demands-Resources(JD-R) theory, the present study is an exploration of the impact of specific personal resources and motivation on job crafting from a perspective of gain spiral. Regrading personal resources, in the present study, we focused on mindfulness, which is a positive cognitive style. Regrading motivation, we focused on work engagement, which is a typical state that allows people to experience positive emotional motives. Job crafting refers to the proactive changes employees make in their job situation. Specifically, employees may proactively increase their job resources(including structural resources and social resources) and challenge job demands, and decrease their hindrance job demands. Mindfulness is considered as the process of drawing novel distinction. Mindfulness includes three dimensions: nevelty seeking, novelty producing, and engagement. Work engagement is a work-related sense of well-being, including vigor, dedication, and absorption. Based on JD-R theory, the present study derived the following three propositions. First, mindfulness as a kind of personal resources can positively predict work engagement. Second, work engagement can positively predict job crafting. Third, mindfulness has a beneficial indirect effect on job crafting through the mediator of work engagement. We conducted a two-wave longitudinal study with the interval of two months to test the hypotheses. Participants in this study were recruited from a top hospital in Beijing. Participation in this longitudinal study was voluntary and confidential. A final sample of 238 medical staff was yielded after screening and matching the two-wave data (65.40% response rate). Among the participants, 80.30% were women. The average age of the participants was 35.96 years (SD = 7.41), ranging from 21 to 54 years. Mindfulness, work engagement and job crafting were reported by participants at both waves. All measuring instruments used in this study were with good reliability and validity in both English and Chinese versions. Mindfulness was measured with the 14-item Langer Mindfulness Scale. The assesment of work engagement was based on the 9-item version of the Utrecht Work Engagement Scale. And job crafting was measured with the 20-item Job Crafting Scale. The results supported the hypotheses. Mindfulness(T1) has a positive effect on craft(T2),β = .19，p < .001. Besides, from the cross-sectional perspective, mindfulness had a positive effect on work engagement, which promotes job crafting sequentially. Moreover, the effect of mindfulness on job crafting was mediated by work engagement (βT1 = .28, βT2 = .14). The 95% confidence intervals excluded zero for the indirect paths through work engagement at T1[.18, .37] and T2[.04, .24] respectively. From the longitudinal perspective, mindfulness(T1) had a positive effect on work engagement(T2). We were not able to detect a significant effect of work engagement(T1) on job crafting(T2) after two months. However, mindfulness(T1) had a beneficial indirect effect on job crafting(T2) through the mediator of work engagement(T2). The 95%CI exclued zero[.01, .17]. The current study was a response to Bakker and Demerouti’s call to explore the important role of personal resources on motivation and job crafting. The present study provided the evidence that mindfulness is a significant personal resources, which is benefical to work engagement and job crafting. Besides, the results provided empirical evidence to extend the JD-R theory to include the gain spiral of personal resources, motivation, and job crafting.