The cohort study was carried out on the data base of infectious diseases in Soc Trang province from 2003 to 2012. The results show that the rate of infectious diseases is highest of model diseases. The rate of some diseases were flu, diarrhea, Dengue fever, etc were high. There is a difficulty of prediction on infectious diseases trend by timeline. Some diseases is more frequency is Dengue fever, and some are down as like as malaria, flu, fecal to mouth diseases etc. acute diarrhea are more frequency in all time. The outbreak of Dengue fever is in May and in November of the year and flu diseases are re-appeared outbreak in 2-3 years.