Posttraumatic growth (PTG) is the most common positive outcome after traumatic events. And, previous studies found that there are many factors have an effect on the developmental process of PTG. The model of PTG of Calhoun and Tedeschi (2006) suggest that social support and deliberate rumination were considered as two important promoting factors. In the fact, Calhoun and Tedeschi (2006) regarded PTG as an important mental result after traumatic experience.However, the PTG model of Hobfoll et al.(2007) and the Janus-face model of PTG (Maercker & Zoellner, 2004) emphasize that PTG also be possible a coping style after trauma, and can predict social support and deliberate rumination. Based on different theories, then many empirical studies found that social support and deliberate have a positive effect on PTG, and PTG also influence social support and deliberate rumination. The relationship among social support, deliberate rumination and PTG were unclear. The reason for it is that the theoretical perspective are different, and the participants of different studies can be different. More importantly, the limits of cross-lagged study on the causal relation can be an important attribution. Therefore, it is necessary to examine the relationship among social support, deliberate rumination and PTG from longitudinal perspective. The current longitudinal study examined the course and bidirectional relation between social support, deliberate rumination and posttraumatic growth (PTG). 245 secondary school students in the most severely affected area were investigated by self-report deliberate rumination, PTSD and PTG questionnaires at 3.5 year 4.5 year and 5.5 year after Wenchuan Earthquake. The cross-lagged structure equation analysis revealed that social support have non-significant effect on deliberate rumination and PTG from 3.5 year to 5.5 year after earthquake. Between 3.5 year and 5.5 year after earthquake, deliberate rumination predicted significantly PTG but not social support. Moreover, PTG predicted significantly deliberate rumination from 3.5 year to 4.5 year but not 4.5 year to 5.5 year after earthquake. In addition, the effect of PTG on social support is non-significant between 3.5 year and 5.5 year after earthquake.