Objective To compare the surgical trauma between videoassisted thoracoscopic surgery(VATS) and conventional thoracotomy, and to investigate the possible minimally invasive mechanism. Methods Seventyseven patients who had undergone consecutive operations from April 2005 to January 2006 were chosen from cardiothoracic surgery department of Fujian Provincial Hospital. Twentytwo cases had spontaneous pneumothorax diagnosed by chest X-ray examination, twentynine had patent ductus arteriosus diagnosed by color echocardiography, and twentysix had congenital atrial septal defect. According to lesions and operative methods, the patients were divided into two groups: conventional thoracotomy group(CTH group) and videoassisted thoracoscopic surgery group(VATS group). The concentrations of serum C-reactive protein(CRP),interleukin6 (IL-6),interleukin-8(IL-8) and tumor necrosis factor-α(TNF-α) were selected as indexes to measure surgical trauma. ARRAY360 specific protein and pharmaceutical analysis system were used to determine CRP automaticly at the day before operation and on the 1st, 2nd and 3rd day after operation. Radioimmunoassay was used to measure the concentrations of IL-6,IL-8 and TNF-α. Clinical indexes such as operative time, cardiopulmonary bypass (CPB) time, intraoperative blood lost, postoperative analgesic time and hospitalization time were analyzed and compared. Results Under the condition that patients had the same diseases, there was no statistical significance in preoperative concentrations of serum CRP,IL-6,IL-8 and TNFα between VATS group and CTH group(P=0.067, 0.062, 0.053,0.064). The concentrations of serum CRP(P=0.045,0.043,0.044), IL-6(P=0.042,0.032,0.039), IL-8(P=0.046,0.045,0.048) and TNF-α(P=0.041,0.043,0.043) on the 1st, 2nd and 3rd day after operation were significantly lower in VATS group than that in CTH group (Plt;0.05). Compared with CTH group, there were less blood lost(P=0.032), shorter postoperative analgesic time and hospitalization time(P=0.041) in VATS group. There was no statistical significance in CPB time between two groups. However, hospitalization time varied with different diseases. Conclusion Compared with conventional thoracotomy,videoassisted thoracoscopic surgery has less surgical trauma, less intraoperative blood lost, shorter postoperative analgesic time, and can make patients recover rapidly. So it is worth spreading.