本文阐述电动机起动应具备的条件，介绍小电网供电系统允许电动机最大起动容量估算的经验式、经验数据和计算公式，重点讨论矿山常用供电系统允许电动机最大起动容量估算和应用方法，以及电动机起动实际压降验算。关键词： 电动机；最大起动容量；估算The paper expatiates the necessary conditions for starting motor and introduces the empirical formula，empirical data and computational formula for estimating the maximum permissible capacity for starting motor from power distribution system of small electric network. The paper emphatically discusses the estimation of maximum permissible capacity for starting motor from power distribution system commonly used in mine，and the checking computation of actual voltage drop at starting motor.Keywords： motor；maximum starting capacity；estimation