The cylindrical gears international accuracy standard ISO 1328-1: 2013（ E） is revised on the old version ISO 1328-1: 1995. To clarify the influence of the latest cylindrical gear international accuracy standard on the gear strength standard GB/T 3480-1997（ idt ISO 6336-1 ,ISO 6336-3: 1996）,the relationship between the gear strength and the gear accuracy is analyzed,the allowable value of single pitch deviation,profile form deviation under the two versions of ISO 1328-1 is listed,and the difference percentage of the two pairs of the instance gears（ 4 gears in total） is calculated,including dynamic factor,transverse load factor（ contact stress）,calculated contact stress,factor of safety from pitting,calculated tooth-root stress,factor of safety from tooth breakage. The instance calculation results shows that the difference percentage of the calculation tooth root stress of gear a is 4. 86%,while gear b is 14. 12%. There is big difference between the two versions of the cylindrical gear international accuracy standards,which will contribute to gear strength calculation standard. More attentions should be paid by someone who using the related standards.