Diarrhea has been the second top leading cause of death among infants around the world (17%). One of five children dies because of diarrhea, due to the loss of body fluid. The aim of this research is to study the relationship between factors that counts for incidence of diarrhea in infants. Data collection had started from March 1st until April 1st, 2012, using polygonal random sampling method to get the sample. From 2401 respondent that fills the questionare,466 families have infants in their home, and as many as 73 infants (15,7 %) had diarrhea for the last two weeks. Majority of the mother gave oral rehidration solution (36,69%) for the main treatment of diarrhea. Significant result was found between the mother’s knowledge and the hand washing behaviour (p=0,001). Furthermore, no significant difference was found between mother’s formal educational level (p=0,649), mother’s knowledge (p=0,124),breast feed behaviour (p=0,031), knowledge about the oral rehydration salt (p=0,000) and the householder’s educational level (p=0,708) with the diarrhea incidence. Mother’s formal educational level counts for a change in the way of thinking. Education level and knowledge without a change to a better lifestyle, and the right way to wash the hands has no relation with the incidence of diarrhea.