Either compressor or vacuum pumps are used in biomass gasification to provide air or take out synthesis gas. Water ring vacuum pumps can be used effectively when gas or air contains condensible steam or vapour, since they utilize sealing water or liquids to create vacuum. In many biomass gasification systems, gas cleaning processes are employed to remove tar and dusts in the syngas. Since water is used to clean up the syngas, water ring vacuum pumps can be adopted to remove tars from syngas as well as vacuum creation. In this study, a water ring vacuum pump was tested whether it can be used to clean up tar from syngas. Experimental results showed that the water ring vacuum pump reduced tar contents in the syngas when temperature of sealing water is controlled by cooling.