Hygroscopic growth characteristics of particulate matter are one of the key issues that need to be addressed in satellite remote sensing of ground-level particulate matter. To solve this problem

the characteristics of the extinction properties of particulate matter as they change with air relative humidity need to be understood

and an accurate hygroscopic growth model of particulate matter should be established. A hygroscopic growth model suitable for Beijing is constructed by using the measurements from instruments deployed on the ground.First

the average particulate matter of mass extinction efficiency is calculated based on continuous measurements from the ground sites in Beijing over a period of two years. Result shows that average mass extinction efficiency of particulate matter increases with relative humidity continuously. The increase in the average particulate matter mass extinction efficiency is moderate when relative humidity increased from 20% to 85%

whereas it increased rapidly when relative humidity increased to 85%. Second

the hygroscopic growth factors of particulate matter in different levels are calculated based on the average particulate matter mass extinction efficiency; the change trend with time of the hygroscopic growth factors are consistent

with the maximum value observed in June and the minimum value in January. From January to June

the hygroscopic growth factors increased before gradually decreasing from July to December. Their values in December were slightly higher than those in January. Third

three hygroscopic growth models commonly used in Beijing are fitted based on these hygroscopic growth factors. The three models showed good applicability in Beijing.The third model is slightly better than the second model

and the second model is slightly better than the first. These models can be used in satellite remote sensing of ground-level particulate matter.