Abstract: Ore-body reserves are the important basis of mine construction and production.At present，the traditional reserves estimation methods cannot meet the requirements of modern mine management.Based on the three-dimensional geological model of ore-body，geostatistics method is an optimal estimation scientific method of block models by analyzing the variation characteristics of ore grade via the theory of regionalized variable.Taking a large iron deposit in Kyrgyzstan as the research object，firstly，the geological data-based and 3D model of ore-body are established; then，the grade-space variogram is obtained by analyzing the grade distribution characteristics of samples; finally，the Kriging interpolation method is adopted to estimate the grade of ore-body，and also the reserves.The research results show that compared with the traditional reserves estimation method，geostatistics method based on the three-dimensional geological model of ore-body and variogram can estimate reserves more scientifically，efficiently and accurately，which is conduced to realize the three-dimensional visualization of mine information and dynamic management of mine resources reserves.

Key words: Geostatistics, Reserves estimation, Theory of regionalized variable, 3D geological model, Block model, Kriging interpolation method