Abstract: Malaysia has abundant, but unutilized oil palm fronds waste. The lack of knowledge on the characteristics of biomass is considered as one of the barriers for not utilizing it as a source of energy. Particularly, determining the moisture content of biomass and reducing it to the required level for the use of thermochemical processes, have remained as a major concern. In this study, the hygroscopic nature of oil palm fronds was investigated and the equilibrium moisture content in a specific laboratory room condition (80% relative humidity and 23°C room temperature) was identified. In the investigation the equilibrium moisture content of oil palm fronds was obtained to be 12% on wet basis. The variation of moisture content of different sections of oil palm fronds with particle density was also investigated and it was found that moisture content has positive correlation with density. For the same moisture content the middle part of the frond was found to be denser than the other sections and the hub section was found to be the least. To investigate the relationship of density with porosity, images of different sections of the frond were taken using scanning electron microscope. The image results showed that the porosity of the middle section is lower than the other two sections while that of the hub section is the highest.