Background: Human salivary α-amylase (HSAA) is the most abundant protein in saliva, has several functions that make it of special interest from a cariogenic point of view, thus may be related to the caries indexes. Purpose: the differences according to the quantified amounts of HSAA in the saliva of children with different caries indexes. Methods: Salivary samples were obtained via spontaneous salivation from a total of 100 children, who were assigned into four groups (n=25 each) according to four categories of the International Caries Detection & Assessment System (ICDAS): sound, white opacity, microcavity and extensive cavity. The total quantity of protein present in each of the samples was determined through the Bradford Method and the concentration of HSAA was determined by an indirect ELISA technique. Non-parametric statistical was perform with Stata 9.2 software. Results: Non-significant statistical differences for variable total protein in the four groups were found. The concentration of HSAA showed statistically significant differences between groups of individuals with white opacity and extensive cavities, microcavity and extensive cavity, and sound and extensive cavity. Conclusions: The findings suggest that from the different functions identified for HSAA, protection of the tooth surfaces has a major relevance.