In recent years, the housing market in China has expanded tremendously due to economic development. Building envelopes have become more and more airtight because of improvements in building technology and concerns on energy conservation. But a lack of knowledge on domestic ventilation performance and difficulties in achieving suitable standards have led to more and more complaints from occupants, and reported cases of building related illness (BRI). For these reasons, we carried out an investigation on indoor air quality and building performance of various residential buildings in a northeast coastal city in China. Field measurement of indoor/outdoor parameters was conducted in combination with questionnaire survey during 2001 - 2002. Statistical analysis was performed to reveal the factors that influence indoor air quality in typical buildings. The relationships between pollutant levels, building characteristics and inhabitants living patterns were also discussed. The conclusions can be summarized as follows: 1. Carbon Dioxide concentration measurements indicated that 1/3 of test rooms were suffering from inadequate ventilation in winter. 2. A total of 29.7% households reported that air in their homes is bad, especially when smoking, excessive occupancy or cooking occurs. 3. The formaldehyde concentration in older houses is lower than in new-built or newly decorated houses. 4. Occurrence of building related symptoms in new dwellings is higher than that in old buildings.