Abstract: Complemented Influence Coefficient Method was used to treat the differential sample in the original data of height and stem diameter index of sunflower in this paper. Using the theory of geo-statistics, the spatial structure of the height and stem diameter index was discussed and its semi-sphere model was established. The results showed that the two growth indexes have good regionalized variable characteristics and spatial structure. After deleting the differetial sample, C₀ is decreased in different degrees. In practice, using this method could offset the shortage of using classical statistics to study on the growing index of crop. Researches on the spatial variability and quantification of the crop information can provide bases for the precision farming.