Dengue Hemorrhagic Fever (DHF) is a disease that became an international public health problem and one of the deadly disease. Based on WHO, Indonesia is a country with second largest number of Dengue cases in the world, after Brazil. Program which involving community is invite people to be willing and able to do 3M plus or PSN in their environment. Prevention of DHF depend on vector control which isAedes Aegepty. This research was held in District Mlati, Sleman. The purpose of this study was to obtain a level of knowledge, attitudes, behaviours, actions, and continuity of the District Mlati community in prevention of Dengue Hemorrhagic Fever (DHF) and Larva Free Index (LFI) in District Mlati. This research was a cross-sectional. Instruments which used for collected data isquestionnaires and forms Larva Free Index. The questionnaire to be used have been tested for validity using content validity and reliability were tested using Cronbach’s alpha. Data were analyzed univariate and bivariate analysis. Analysis result showed there was no correlation between sociodemographic and actions, Analysis result between independent variables and independent shows there is no correlation between knowledge and attitudes towards action. Based on the values obtained, District Mlati include areas with potential againts the spread of DHF but in the safe category of the extraordinary occurence of DHF 
Keywords : Dengue Hemorrhagic Fever (DHF), Larva Free Index, Mlati