近年来,普遍采用塑性应变比 r 和形变强化指数 n 这两个参数来标志薄板冲压成形性能,但其测定方法大都各行其是,迄今尚无统一标准可循。本文对 r 值和 n 值的现行定义公式加以推导简化,使测定方法和数据处理简便易行。同时,引出薄板板面形变强化各向异性指数Δn,用以衡量板面各向成形极限差异. In recent years, the two parameters of plastic strain ratio r and deformation enhancement index n are commonly used to mark the sheet metal stamping formability. However, most of the measurement methods are in line with each other. So far there is no uniform standard to follow. In this paper, the current definition formula of r value and n value is deduced and simplified, which makes the measurement method and data processing simple and easy. In the meantime, the anisotropy index Δn of deformation of sheet metal is deduced, which is used to measure the difference of forming limit in different directions.