The previous studies have reported that compared deoiled POME and the raw POME on the methane production (Fang et al. (2011). It lake a information influence of organic fraction (Demirer, 2004; Raposo et al., 2008; Zhang et al., 2007). Organic contained in the wastewater might inhibit the process, so dilution of the wastewater might also influence significantly the practical methane potential. Therefore, dilution should be done when a substrate is used for the first time, to ensure that possible toxicity of the sample is not overseen.