The objectives of this research were to investigate risk factors for Dengue fever in Thailand and to select an appropriate model. The generalized estimating equation (GEE) whose dependent variable has a Poisson distribution and a negative binomial distribution were studied. The secondary data consisting of the number of Dengue fever patients rainfall average temperature forest area household income were collected. Regions and seasons were also considered. The research found that the GEE whose dependent variable has a negative binomial is more appropriate to be used for Dengue patient data analysis. Central region and the season during Feb-Apr were assigned to be reference groups. Risk factors for Dengue fever were rainfall (Relative Risk (RR) = 1.0009) average temperature (RR = 1.1736) forest area (RR = 1.0482) southern region (RR = 2.7390) eastern region (RR = 2.0489) western region (RR = 1.4051) the season during May-Jul (RR = 3.0526) and Aug-Oct (RR = 3.2677)