This paper estimates Japanese average marginal tax rates on factor incomes around the time of the Lehman Brothers collapse. For this purpose, the paper uses the 93SNA (2005 Standard) data and the methodology of Gunji and Miyazaki (2011). The findings are as follows. The tax rates on capital incomes are higher based on the 2005 Standard than the 2000 Standard. In 2008, the average marginal tax rates on labor incomes were stable, whereas those on capital incomes increased. The growth rate for Japan's GDP and the capital tax rate have a negative correlation. Compared to the dramatic drop in capital incomes, capital tax payments declined gradually.