Thus, a survey on Knowledge and Attitudes among people on vaccines which are free of charge and some new vaccines for purchasing (Vaccine 6/1, Rotavirus vaccine, cervical cancer vaccine) is necessary for the clinician and policy maker. Objectives: to evaluate Knowledge, Attitudes of mothers on immunization in Expanding Program on Immunization (EPI) and 3 purchasing vaccines. Method: this was a cross - sectional study, conducted on 556 mothers with under 1 year-old children who live in Tan Phu district and brought their children to the Pediatric hospital N02 for vaccination by using clusters sampling technique.