Abstract: In order to study the effects of salt mixtures on dry matter accumulation and photosynthetic characteristics of flue-cured tobacco and also the influences of salt stress on leaf growth and development, a pot experiment on cv. Zhongyan 100 was carried out. On the basis of average salt concentrations in the soils from the main tobacco areas in Luoyang, the effects of combined treatments of seven salt ions (Ca²⁺, Mg²⁺, K⁺, Na⁺, HCO₃^-, SO₄^2- and Cl^-) at the concentrations of 0.013 2, 0.068 3, 0.123 4, 0.178 5 and 0.233 6 mol·kg^-1 on the agronomic traits, dry matter accumulation, photosynthetic characteristics, proline and malondialdehyde contents of flue-cured tobacco were investigated. The results showed that the salt mixture treatments slightly affected the number of leaves. With the increase in salt concentrations, the agronomic traits (except for plant height and effective leaf number), dry matter accumulation, photosynthetic index (except for intercellular CO₂ concentration) and proline content increased first and then decreased, peaking at the concentration of 0.068 3 mol·kg^-1. The content of malondialdehyde increased continuously. Therefore, the salt mixture treatment at the concentration from 0.123 4 mol·kg^-1 to 0.233 6 mol·kg^-1 damaged the photosynthetic system and reduced the dry matter accumulation of tobacco plants, while the treatment at the concentration of 0.068 3 mol·kg^-1 promoted the photosynthesis of tobacco leaves and the growth of flue-cured tobacco.