Abstract: In this paper, 470 broadband seismic records of natural earthquakes with M≥4.0 between May 2014 and May 2019 recorded by 121 fixed stations in and around Yunnan Province are collected. 6 976 high-quality vertical wave data is processed by using the reverse two-station method. The attenuation imaging of Lg wave at 1 Hz with spatial resolution less than 100 km in Yunnan area is inverted. The inversion results show that the Q₀ value of Lg wave in Yunnan is in 60 to 300 range, and the whole is in low Q₀ background, with significant changes in lateral heterogeneity. The distribution characteristics of low Q₀ value in Yunnan area reflect the strong attenuation of Lg wave in Yunnan area. The Q₀ value in the west side of Honghe fault is relatively low, in 50 to 160 range, and in the east side is relatively high, in 120 to 200 range. The distribution characteristics are consistent with the distribution of sedimentary layer thickness. Loose sedimentary layer may be the main cause of high attenuation in the east side. The Q₀ value of Lg wave in Yunnan area shows a similar differential distribution with the distribution of surface heat flow, which may be related to frequent earthquakes, long-term strong tectonic movement and deep material upwelling with volcanic activity.