质 量和密度是力学中的两个最基本的物理量 ,对密度概念的理解、利用密度公式解决实际问题以及测物质密度的实验等 ,均是各地中考及竞赛中重点检测的内容之一 ,其题型也由以往的单一性实验被现在的开放性或设计性实验所取代 .本文将与密度相关的几个特殊问题进行归类分析 ,供大 Quality and density are the two most basic physical quantities in mechanics. The understanding of the concept of density, the use of density formulas to solve practical problems, and the experiment of measuring the density of materials are all part of the focus of testing in the national exams and contests. Types have also been replaced by existing openness or design experiments from previous singleness experiments. This paper classifies and analyzes several special issues related to density.