The content of protein and oil in soybeans is an important trait for evaluating quality and is regulated by genetic and environmental factors, lacking comprehensive identification under a variety of ecological conditions. Therefore, evaluating the stability of soybean quality traits under different environmental conditions has great significance for various applications. In this study, we compare 150 soybean varieties from Northeast China (Group A and Group B) and the Huang-Huai-Hai region (Group C). As the release time progressed, the oil content in the soybean varieties showed an upward trend in both Northeast China and the Huang-Huai-Hai region, while the protein content showed a downward trend. Additionally, the oil contents were negatively correlated with the protein contents and the sum of protein and oil contents, while the protein contents were positively correlated with the sum of protein and oil contents, with the correlation becoming stronger as the latitude decreased. Moreover, there were obvious variations in quality stability among different varieties. Hefeng 45, Jilinxiaolidou 4, and Zhonghuang 19 had relatively high protein contents and exhibited good stability across different environments, while Kenjiandou 25, Changnong 17, Dongnong 46, Kennong 17, Liaodou 14, and GR8836 had relatively high oil contents with good stability performance in varying environments.