The maximum geld growth range of wheat yield per unit in China is analyzed from three aspects including photosynthesis production potential of wheat, the changing trend of per unit wheat in the previous years and potential of distribution area agricultural crops. In the paper, me potential of using light, the external potential of historical yield evolution tend and AEZ (agricultural ecological zone) are applied to calculate the per unit yield potential of Chinese wheat. The results assume that the maximum growth range of per unit yield in different stages was different, before 1991 , the growth range was 10% ;before 1996, me growth range was 9% ; before 2000, the growth range was 8%. Any variety of wheat and planting technology higher than the above growth range can only be promoted in restricted area and has the statistical error. The results are of reference significance to Chinese wheat production.