Abstract : Early childhood caries or ECC is the most dominant disease in childhood that affecting many children in each country of the world. This study aimed at the application of response surface methodology (RSM) to model the risk factor contributes to early childhood caries based on the contour plot. Contour plot is a helpful visualization of the surface when the factors are no more than three. When there are more than three design variables, it is almost impossible to visualize the surface. The result shows only three variables have the relationship between the number of caries such as the status of caries (5.0973, p = 0.000), the income of the family (0.0009, p = 0.003) and types of water (-0.7927, p = 0.049). On the other hand, severe ECC experience is an important predictor of caries among children. High-income families can buy more sweets and snacks than others which is a contributory factor in creating dental caries among children. Through this study, the significant result is very important especially toward early children and especially their parents to prevent this problem. On the other hand, the government and health professional organizations should monitor the groundwater quality regularly which is used directly without treatment as drinking water.