We examined the differences between absorbable staple and un-absorbable staple in inflammatory reaction during the early post-operative period in lung cancer patients. From october 1993 to august 1994, absorbable staples (GIA 75-.060; United States Surgical Co., Ltd.) or un-absorbable staples (Multifire GIS 60 Titanium (3.8mm); United States Surgical Co., Ltd.) were applied in 10 lung cancer patients each. Duration of air leakage, massive pleural effuion (more than 100 ml/day), and high fever (over 38 degrees C), as well as the changes of leukocyte counts in peripheral venous blood and C reactive protein were compared between the two groups. The absorbable staple group show a mildly increased inflammatory reactions than those of un-absorbable staple group, but those were not significant differences. Absorbable staple was shown to be completely absorbed until 6 months in animal model. Absorbable staple is thought to be superior to un-absorbable staple, instead of mildly increased inflammatory reaction during the early post-operative period.