Rampant caries is a type of dental caries and children with this disease suffer much pain and problems. Because of the protective role of saliva that may be impaired in these children, relation between the saliva and rampant caries is determined. For this purpose the paraffin-wax stimulated whole saliva was estimated in 117 physically healthy children aged.4-5 yr that have deciduous dentition. Children were categorize in three groups. First with rampant caries (Case), second, with average DMFT (Control) and third caries-free children (Control 2). Each group composed 39 children. The rate of flow was determined during sample collection. Calcium, phosphate, PH, and buffering capacity of samples were analysed biochemically. The results were analysed with ANOVA.The rate of flow, PH & buffering capacity of samples from children involved with rampant caries were lower than control groups. t-lest for the differences between groups were statistically significant only for PH & salivary rate of flow (p<0.05). The mean levels of both Calcium and Phosphate in saliva were higher in children with rampant caries but only for phosphate differences reached statistical significancy (P<0.05).Although it seems that there is some personal differences in saliva which lead to rampant caries but more studies in this topic are required.