Abstract: A survey of the yields of wheat crops in Peking area and in the sample fields were analysed. The levels of cultural management can be divided into eight categories, according to the correlation between the number of heads per mu and the averageweight of individual head. These categories for classification can be used as a standard for the measurement of suitable planting density. Several examples were given to explain the application of this kind of classification in field production. Based on the relationship between planting density and number of heads; the performance of plant sbearing larger or smaller number of ears and the requirement of various numbers of heads in different cultivating conditions, certain principles and quantitative indexes for determining the planting rate and seeding rate were suggested.