Objective To know the indoor air pollution status in the newly decorated residential houses in Jiaozuo and to study the effect of decoration materials on the pollution. Methods To monitor formaldehyde, ammonia and benzene levels in the indoor air of 39 newly decorated rooms in Jiaozuo. Results The exceed standard rates of formaldehyde, ammonia and benzene in the indoor air were 73.6%, 84.7% and 25.8% respectively. Exceed standard rate of formaldehyde in the room which held the new furniture was the highest, 88.8%. Conclusion Decoration may cause indoor air pollution, the most part of the pollutants are formaldehyde and benzene. The level of the pollution depends on the different usages of the rooms.