He taught literature to Kim Il Sung for a short time at Yuwen Middle School in Manchuria.

In China, he is primarily known for his work on the idea of the sprouts of capitalism: that proto-capitalism and class struggle had existed in the earlier Chinese history.

[7] Shang's daughter later attested that her father had thought of Kim as "diligent, putting good questions both inside and outside the class.

[7] He was one of the historians in Mainland China who contributed to the idea of the sprouts of capitalism, describing features of the economies of the late Ming and early Qing dynasties.

[1] Shang Yue lived and worked during his career at Jilin, Harbin, Shanghai, Beijing, Hankou, Chongqing, Ningxia and Yan'an.

[11] The core argument of Shang Yue's idea on the sprouts of capitalism is that proto-capitalism existed under late Ming and early Qing China from the 16th to the 17th century, as evidenced from large quantities of factory products that entered metropolitan markets.

[8] Shang Yue's work was part of the efforts by Chinese historians to make the formation of Communist China seem like a natural outcome.

Mao claimed that bourgeois and proletarian classes did not exist before the imperialist powers started to affect China after the Opium war.

Liu Danian [zh] complained that Shang Yue's theory glorified opium trade as a progressive force, and degraded Qing government and its subjects for active resistance.

Jungmin Seo argues that reactions to Shang's theory show Chinese historians' fear that greater emphasis on internal proto-capitalism might divert too much attention from foreign capitalism's influence that transformed China into a semi-colonial or semi-feudal status.