Abstract: Solid model is the model which has been developed in recent years. It can depict ore-body,calculate the reserve of ore-body, and keep geology information better. But, many problems must be solved before the grade is directly estimated on solid model. One is bigger of calculation amount,another is conflicting with the fundamental principle of geostatistics. Aimed at the condition, this paper will discuss how to establish solid model and how to estimate grade on solid model in detail.