Abstract: To improve the quality of cured leaf, the yellowing section was divided into front and rear yellowing sections, the colour-fixing section was divided into front and rear colour-fixing sections according to the positions of curtains in the advecting airflow stepping type flue-curing barn. The temperature and humidity distribution in the barn was determined at different trolley distances. The suitable ranges of trolley distance in the four sections were 30-35cm, 25-30cm, 15-20cm, and 10-15cm, respectively. The optimum heights of curtains which influenced air current, damp dissipation,temperature and humidity distribution in the barn determined at the suitable trolleydistances was 120cm in front yellowing section, 90cm in rear yellowing section, 60cm in front colour-fixing section and 50cm in rear colour-fixing section. The quality of cured leaf was improved and the proportion of high quality leaves was increased while the trolley distances and curtain heights were properly set.