OBJECTIVE To explore the relationship between immunochemical level of salivary and caries in children aged 4-6 years old. METHODS Two groups were assorted as patients with caries and without caries. Every group included 45 people. Measurements of salivary secretory immunoglobulin A (SIgA)were performed by using radio-immunoassay and single agar diffusion assay. The levels of lysozyme (LZ), alkaline phosphatase (ALP) and lactic dehydrogenase (LDH) were studied with colorimetry and turbidimentry. RESULTS The levels of LDH, SigA, ALP, LZ had significant difference between the two groups (P < 0.05). The level of LDH between patients and peoples without caries had little difference (P > 0.05). CONCLUSION The incidence of caries is associated with age, and it may have association with immunochemical levels of salivary.