This paper, based on China's land supply data from 2010 to 2018 gained from China Land Market website via Python program, uses spatial distribution center, regional Gini coefficient, cold-hot spot and panel data model to discuss the temporal-spatial evolution and mechanism industrial land supply in Yangtze river economic zone during bi-transitional periods of market and development and supply side reform, aiming at providing theoretical supports for optimizing industrial planning and promoting supply side reform. Supply of industrial land in Yangtze river economic zone shows a fluctuated decreasing trend with rising, falling and slowly increasing stages. Spatial distribution of industrial land citywide generally tends to be balanced with a shrinking regional land supply difference. Industrial land is the largest in the middle stream of Yangtze river with its distributing center migrating to Yangtze river delta. Land supply is influenced by industrial land price and economic level; it is promoted by increment of fixed asset investment, local financial income and gross industrial production.