Objective To understand the indoor air quality in some residential houses decorated for different times in Shijiazhuang, China. Methods To monitor formaldehyde, ammonia, benzene, toluene and dimethylbenzene levels in indoor air of 220 rooms decorated within 2 years. Results The exceed standard rates of formaldehyde, ammonia, benzene, toluene and dimethylbenzene in indoor air were 51.63%, 42.13%, 5.39%, 7.46% and 7.69% respectively. The exceed standard rate of indoor air was the highest, 66.13%, in rooms decorated for 3 months. Conclusion Indoor air pollution caused by decoration is serious in Shijiazhuang. A correct choice of decoration materials and ventilation is essential to avoid the human heath damage caused by indoor air pollution.