Abstract: Based on the long-term observation data of aerosol optical properties at Longfengshan regional background station in Heilongjiang province from 2010 to 2020, the variation of aerosol optical depth, Angström exponent, single scattering albedo, particle volume size distribution, and aerosol direct radiative effect were analyzed.The results show that the maximum aerosol optical depth in the background area appears in July, with an average value of 0.67.The smaller values occur in December, January, and February, with an average value of 0.17, 0.02, and 0.18, respectively.The daily aerosol optical depth reaches the highest value of 0.39 at 17:00. The Angström exponent decreases significantly in April and May, with an average value of 1.20 and 1.21, respectively.The Angström exponent reaches the largest value in December, with an average value of 1.74.The low value of single scattering albedo (SSA) occurs in April, August, and October, with the average values of 0.84, 0.82, and 0.84, respectively.The peak Angström exponent reaches 1.44 at noon.The maximum volume of coarse mode particles appears in May, which is about 0.04 μm³·μm^-2, and the effective radius is about 3.85 μm.The maximum volume of fine mode particles is 0.06 μm³·μm^-2 with an effective radius of 0.19 μm appeared in July.In autumn and winter, the volume of fine and coarse mode particles further decreases in Longfengshan.The maximum values of aerosol direct radiative effect at the ground and on the top of the atmosphere appear in July with values of -94.44 W·m^-2 and -22.33 W·m^-2, respectively.