Prokaryotic and eukaryotic cells respond to heat stress and other environmental abuses by synthesizing a small set of stress proteins and by inhibiting post-transcription synthesis of normal proteins. The purpose of the present study was to document the stress response produced by inflamed gingival tissue in vivo, and cytokine induced human periodontal ligament cells. Human PDL cells were exposed to TNF-alpha(1ng/ml), INF-gamma(200 U/ml), LPS(100ug/ml), combination of cytokine, and SDS-PAGE gels running and Western blotting analysis was done. In vivo studies, the healthy gingival tissusse of a control group and inflamed gingival tissue of adult periodontitis were studied by immunohistochemistry and histology. The results were as follows 1. HSP 47 was distributed on basal layer in healthy gingiva, but stronger stained in basal, suprabasal, and spinous layer of inflamed gingiva. 2. HSP 47 was rare on endothelial cells and mononuclear cells in healthy gingiva, but stronger expressed in inflamed gingira. 3. HSP 70 expression was rare on epihelium and inflammatory cells in both healthy & inflamed gingiva. 4. HSP 70 was actively expressed on endothelial cells and inflammatory cells of capillary lumen in moderately & mild inflamend gingiva. 5. PDL cells showed low level of HSP 47 protein expression which was significantly induced by cytokine stimulation(LSP only and combination). 6. Maximum HSP 70 protein induction was seen with stimulation by a combination of the cytokine, Combination of TNF-alpha, INF-gamma, LPS have been shown to synergistically effects of HSP 70 expression. On the above findings, HSP is influenced by cytokine and chronic inflammation in vivo, and may be involved in protection of tissue during periodontal inflammatiom.