The purpose of this study is to examine the income inequality of forestry households using the raw data of the Forestry Household Economy Survey from 2018 to 2022, and to identify the factors which affect the income inequality. To that end, we analyze the income inequality trend and determine whether the polarization of income distribution is present. The determinants of income inequality are examined through the decomposition of inequality by income source and population subgroups. The results show that income inequality and polarization are gradually intensifying due to both the income decline for the low-income group and concentration of income toward the high-income group. In addition, we find that most of the increase in inequality is attributed to forestry households with forest lands less than 1ha. Particularly, the income inequality is expected to increase as the proportion of single-person households increased. Forestry income is the income source that has the most influence on the income inequality. It is found that forestry subsidies is insufficient to reduce the inequality. For maintaining forestry and forestry households and decreasing the income inequality, these results suggested to expand forestry subsidies for forestry households with low income.