To improve the effectiveness of Preventive Medicine team in District health center, its needed to do the workload of health workers based on their functions and tasks. Cross sectional study with both quantitative and qualitative data collection was carried out with 47 staff working in 4 district preventive medical teams in Khanh Hoa province with the goal of determining the workload of medical staff and district preventive medical team. The data analysis was conducted with SPSS 16.0. The results were showed the variety of number of national targeted programs among district team (7-11 programs). The average time that medical staff spend for three main tasks is different, namely: time for the monitoring of patients! assessing community environment (450h to 698,4h), supervision of the commune activities (287h to 417,3h) and monitoring activities at the local areas (146,6h to 558,9h). The time spent for other professional works is varied. between 269h to 660h and nonprofessional works between 87,1h to 112,9h. Some recommendations were made such as to develop the job analysis and job description to make sufficient plan of human resource, better collaborate with other sectors to get information on the epidemics such as malaria, dangue fever etc. Also it is needed to work with curative sector to prevent the transmission of epidemics.