As a part of host factors of dental caries, saliva has been well known for its important role in relation to dental caries. The studies on its physical and chemical characteristics on development and progress of dental caries has been conducted. Recently, various comparisons between saliva of caries-susceptable individuals and caries-free individuals has been done and the efforts to understand the mechanisms of salivary intervention of development and progress of dental caries is actively in progress. In this study, 15 children with rampant dental caries and 15 caries free children without any systemic diseases from the ages of 2 to 5 were chosen for the experiment and the whole saliva and parotid saliva from each individuals were collected and protein compositions were compared using polyacrylamide gel electrophoresis (PAGE). As results of this study, in parotid saliva, there was no difference in protein compositions between the rampant dental caries and the caries free children. While electrophoresis was done with the whole saliva, protein with 120 KDa was found in children with rampant dental caries. However, this protein was not found or unclear, if any for the caries free group. (Exceptionally, clear protein band was present for one person.) Protein compositions of whole saliva of rampant dental caries group was compared before and after the caries control and thick and clear protein bands of about 120 KDa were found in both cases. Protein compostions of caries free children and adults were identical. Quantitative analysis of protein was done for the rampant dental caries group and the control group and no significant difference was found. Taken all together, protein with molecular weight of 120 KDa, found in rampant dental caries group, was still present when the treatment for the dental caries was done so it can be assumed that this protein has no interrelation with the presence of active carious lesions during saliva collecting. It can also be presumed that this specific salivary protein with the molecular weight of 120 KDa found in rampant dental caries group has effect on development and progress of dental caries. Identification on this protein with the molecular-weight of 120 KDa and the role of this protein against dental caries remain to be solved.