Abstract: Based on the research into the tree cotton within cropping structure in Shandong before mid-Ming Dynasty, the process of the introduction of tree cotton was described. The popularization of tree cotton changed the traditional cropping structure, which in turn resulted in a dramatic change in raw material for clothing and quilt as well as a huge impact on economy, society, agricultural production and people’s life alike. From the angle of history and biology, the practical and commercial values of tree cotton were fully discussed. The causes for the popularization of tree cotton in Shandong vary from governmental policies to its adaptability to increasing social and economic demand for cotton. The successful introduction and large-scale popularization of tree cotton is a milestone in the history of economic development and also an important revolution in the history of agriculture in China.