Abstract: Based on analysis of the aerosol hygroscopic parameter (κ) and the aerosol ionic components observed in July 2014 in Huangshan Mountain, characteristics of the multi-size aerosol hygroscopic parameter (κ) was investigated and a parameterization scheme of κ was developed. Results indicate that the sampling site was mainly affected by southwesterly, northerly and southeasterly flows during the summer. The value of κ varies from 0.2 to 0.48, and it first increases and then decreases with the increase in the aerosol particle size. When the aerosol particle size is within the highly hygroscopic range of 0.15 to 1.1 μm, the κ value is greater than 0.3; when the aerosol particle size is within the range of less hygroscopic, the value of κ is smaller than 0.3. For those aerosol particles with a diameter Dpμm, the highest value of κ appears when influenced by southwesterly flow, and the lowest value appears when southeasterly flow is prevalent. The opposite is true for aerosol particles with a diameter Dp>1.1 μm. The main water-soluble chemical components of aerosol particles are NH4+, SO42- and WSOC, which affect the hygroscopicity of aerosol particles with a size smaller than 1.1 μm. NH4+, SO42-, NO3-, WSOC and Ca2+ are the main soluble chemical components that affect the hygroscopicity of aerosol particles with a size greater than 1.1 μm. The parametric equation of κ for aerosol particles with a size less than 1.1 μm is κreg=0.12+0.45fNH4++0.63fSO42-+0.18fWSOC, and the equation for aerosol particles with a size greater than 1.1 μm is κreg=0.01+0.78fNH4++0.76fNO3-+0.8fSO42--0.28fCa2++0.14fWSOC(f is the mass percentage of the corresponding component). Both equations can well predict the values of κ for multi-size aerosol particles, and the deviations of predicted values are less than 30%. The forecast values of κreg are highly correlated with calculated values of κ, and the correlation passes the significance test at the 99% confidence level.