The present study was conducted with the objective to understand the bark protein profiles of healthy and TPD-affected Hevea. Soft bark tissues were collected (2-3mm thick laticiferous tissue adjacent to the cambium) from both fully dry and healthy trees of clone RRII 105. The tissue was homogenized in borate buffer (pH 9.0) and the total buffer soluble protein was extracted and estimated. The extract was then subjected firstly to 85 C and subsequently 95 C heat treatment for 20 minutes. The heat stable proteins were collected and estimated. The crude extract and heat stable fractions (HSFs) were further analyzed by electrophoretic separation (SDS-PAGE). In addition, the C-serum proteins in healthy and late dripping trees were tested for the presence of stress induced LEA group of proteins. The buffer soluble protein content did not differ significantly in either the crude extract or HSF at 85 C between TPD-affected and healthy trees. However, in the HSF at 95 C proteins were significantly higher in the healthy trees versus the TPD-affected trees. When shocked at 85 C there was a 25;reduction in the protein content of the crude extract as against 31;in case of TPD-affected bark. These reductions were 51;and 58;at 95 C in the healthy and TPD-affected bark, respectively. These results suggest that the bark proteins of Hevea are remarkably tolerant to heat shock. The protein profile analysis by SDS-PAGE revealed the presence of a protein (approx. 7kDa) in TPD-affected bark in relatively higher quantities which seemed to be relatively heat stable. In addition to this, some new sets of heat stable proteins in the lower molecular weight range(<30kDa) were also noticed in TPD-affected bark. Further investigations on the significance of these proteins are in progress. A dot-blot analysis using LEA-2 and LEA-3 group polyclonal antibodies revealed the presence of LEA proteins in the C-serum in both healthy and late dripping trees. The LEA and heat stable proteins are known to impart stress tolerance in plants. Hence, their role in TPD is being investigated.