Abstract: OBJECTIVE To study the impact of thoracoscopic surgery on the postoperative infection and pain stress related blood indexes of children with mediastinal tumor,in order to understand the clinical application value of the surgery. METHODS A total of 64 children with mediastinal tumor who were treated with surgery in our hospital from Jan. 2012 to Jan. 2016 were selected as study objects,and were randomly divided into control group and observation group, with 32 cases in each group. Children of control group were treated with traditional open chest surgery,and of observation group were treated with thoracoscopic surgery,then the postoperative infection rates,pain stress related blood indexes before and after the surgery of the two groups were analyzed and compared. RESULTS The total postoperative infection rate of observation group was 3.13%,which was lower than 12.50% of control group. The pain stress related blood indexes of 5-HT,PGE2,BK,and NPY of the two groups before the surgery had no significant difference. At 12 and 24 hour after the surgery, the pain stress related blood indexes of 5-HT,PGE2,BK,and NPY of observation group were all significantly lower than those of control group,the differences of two groups were all significant (all P＜0.05). The other pain stress related blood indexes of NO, IL-1β and IL-6 of the two groups before the surgery had no significant difference. At 12 and 24 hour after the surgery, the pain stress related blood indexes of NO, IL-1β and IL-6 of observation group were all significantly lower than those of control group,the differences of two groups were all significant (all P＜0.05). CONCLUSION The control effect of thoracoscopic surgery for the postoperative infection and pain stress related blood indexes of children with mediastinal tumor is better,so the surgery method is more suitable for the children with mediastinal tumor,and its clinical application value is higher.