The purpose of the study is to estimate the air quality improvement in the urban areas of HoChiMinh City (HCMC) through resident's willingness to pay (WTP) by using contingent valuation method. 300 residents were chosen to participate in an interview with the structured questionnaire and the open-ended question about their WTP. The results show that with the performance of ambient air in HCMC, 88.41% of respondents are willing to pay for this "particular commodity". The average WTP for a 50% reduction of concentration of air pollutants in next 5 years in HCMC, where respondents live and work was 19,732 VNĐ/household/month, accounted 0.15% of a household income. Positive WTP values reveal that residents have a choice between better air quality and rapid growth of the economy, which also means that air quality is really their considerable economic value. Therefore, this value should be considered in the costbenefit analysis of projects or programs relating to air quality. The results are the source of useful information for policy makers to decide in the investment and policy measures to reduce impacts on air quality in the process of economic development.