The formulas on crack width of rc beams and src beams are analyzed at home and abroad too . the calculation formulas on the maximum crack width of src beam under short time load are suggested . the calculation result tallies that of tests well 分析比较了国内外钢筋混凝土梁和劲性钢筋混凝土梁裂缝计算公式，提出了劲性钢筋混凝土梁在短期荷载作用下的最大裂缝宽度计算公式，其计算值与试验值吻合较好。
