Based on the single scatter model （Sato）, using 48 earthquake wave form data with ML≥2.0 from January in 2004 to September in 2007 recorded by the Chongqing earthquake net, the Qc values of coda in Rongchang region is calculated, and relationship between Qc value and frequency is polyfitted. The result indicates that this region is low Qc value but dependence on frequency strongly. In addition, studied on Qc value in three segments of time, the result display that coda wave Qc value are steady in each segment, and the configuration of medium underground is steady in the region and each segment of time too.