目的　研究正常成人肺HRCT呼气相表现和对其进行定量分析。方法　分析 97例 2 0～ 70岁健康志愿者的肺呼气相HRCT表现 ,计算双肺吸呼气相密度差值 (VD)、面积缩小率 (AR)、呼气相上左前、左后、右前、右后肺局部区域的密度值 (LD) ,并对其进行统计学分析。结果　左肺与右肺之间 ,上肺与下肺之间的VD和AR存在显著性差异 ;前肺与后肺的LD有显著性差异 ;双肺的VD和AR有显著性相关。结论　健康成人的肺呼气相HRCT上各区域间存在着密度差异。 Objective To study the performance of normal adult pulmonary HRCT expiratory and quantitative analysis. Methods The pulmonary expiratory HRCT findings of 97 healthy volunteers aged 20 to 70 years were analyzed. The differences of breath density (VD), area reduction (AR) The densities (LDs) of the right anterior and posterior lung regions were calculated and statistically analyzed. Results There was a significant difference between left and right lungs, between upper and lower lungs. There was a significant difference between LD and AR in the anterior and posterior lungs. There was a significant correlation between VD and AR in both lungs. Conclusion There are density differences among regions of lung expiratory HRCT in healthy adults.