Up till now, exploration geochemistry has been mainly devoted to the appraisal of low and gentle anomalies or indistinct weak anomalies. It is very difficult to attain the aim of geochemical prospecting merely on the basis of traditional methods for finding and evaluating anomalies. With the geochemical theoretical system and methodology as the basis, this. paper attempts to expound the systematicness of geochemical ore prognosis from the angle of systematic engineering. Guided by the systematicness, we could perform geochemical prediction. It consists of three aspects: geochemical theoretical system and methodology make up its basis) geochemical prognosis is the prediction at different levels; the geochemical prognostic system is an integrated prognostic system.