电热法是油品比热容物理实验中一种常用的测量方法，实验中加热功率的不稳定因素导致输入总热量无法精确定量而给结果带来一定的误差.本文基于牛顿冷却定律，推导了不同质量油品测试样品的系统比热容与散热速度的关系，设计了通过改变被测油品的质量确定其比热容的测量方案.实验测量结果表明，冷却变质量法的测量相对误差可控制在3%以内，测 量过程与数据处理简便且该方法完全不受加热功率不稳定因素的影响.

The electric heating method is a common method used in the liquid specific heat capacity measurement experiment，a part of the experiment error comes from the changing heating power that leads to difficulty in accurately calculating total quantity of the heat. Based on the Newton's law of cooling，the relationship between the heat capacity of the system and the cooling speed of the system is derived under the condition of different quality of the oil test samples and the measuring scheme for oil specific heat capacity is designed. The experimental result shows that the measuring relative error of the method proposed in the paper can be less than 0.03. The advantages of this method are the operability，simple data processing and anti-interference of unstable heating power.