The continuous evaluation of geology (mineralization) is the basis of mineral exploration and resource estimation.The nugget effect is the ratio of the nugget variance to the total variance in the variogram,which can be used to describe the variability of the spatial structure of geological variables and has important influence on grade estimation.In practice,however,the fitting of variogram and geological interpretation of nugget effect are subjective and arbitrary.Based on the previous studies,the paper mainly discussed the main factors influencing the nugget effect in variogram,systematically elucidated the indication of the nugget effect on geological (mineralization) continuity,and the significance on kriging and IDW grade estimation.The study is practical for mineral exploration evaluation and resource estimation to improve their reliability.