Gingival crevicular fluid (GCF) is a promising source for markers of destructive periodontal disease activity. This study was undertaken to evaluate the protein composition of GCF in varying stages of the gingival inflammatory response. GCF sampled from 26 people with clinically healthy gingiva and 18 people with periodontitis were examined via sodium dodecyl sulphate polyacrylamide gel electrophoresis(SDS/PAGE). The result were as follows. 1. Total amount of GCF protein of diseased group significantly different from that of normal group. But difference in protein concentration was not that significant. 2. In analyzing GCF with SDS/PAGE, it was suggested that albumin is used as indicator plasma protein leakage because of heavily staining bond of albumin in patients with periodontal disease. 3. In diseased group, overall bonds of protein and bands of high molecular weight protein were heavily stained. It was proved useful information on high molecular plasma protein leakage with increasing vascular permeability due to inflammation.