Based on the discussion on the principle of density - logging , this paper analyses far - gamma gamma rate , near - gamma gamma rate and density - logging curve respectively , and discusses far - gamma gamma rate near - gamma gamma rate and density variation caused by radioactive anomalies , and preliminarily interprets factors that could lead to the variation of density - logging curve of radioactive anomalous layer , thus explaining the reason why density - logging curve changes at the radioactive ore - layer in northern ordos basin , finally , an empirical formula for revising the distortion of density - logging curve has been established 摘要本文概述了密度测井原理，分别对长源距计数率、短源距计数率及密度曲线进行分析，对由于放射性异常引起的长源距计数率、短源距计数率及密度变化情况进行了讨论，初步解释了放射性异常层位密度曲线的变化因素，说明了鄂尔多斯盆地北部地区密度测井曲线在放射性矿段的变化原因。
