Abstract: In order to research the relation between composition of chromite and ore content of kimberlite, samples were obtained from Wafangdian orefield in Liaoning and Mengyin orefield in Shandong for micro-area chemical composition analysis of chromite in kimberlite pipe by electronic probe spectrum. The result indicates that the chemical compositions of the chromite vary in different generations, particularly for chrome and aluminum. The value of Cr'=Cr/(Cr+Al) is used to represent the relation between chromite and the ore-bearing potentiality of kimberlite. The Cr' values of chromite decrease with the increasing diamond contents in kimberlite, which is a significant guide for prospecting mineralogy.