The speed difference of strip between two stands is the origin of strip tension in tandem rolling process. The relation between elastic elongation and tension meets Hooke′s law, and the elastic elongation of strip produces speed difference. Based on these principles, the tension differential equations were derived for rolling strip with uniform and variant strip sections with one step or n-1 step disturbance points. The simplified forms of these equations are the same as reported in other references. The speed difference of strip between two stands is the origin of strip tension in tandem rolling process. The relation between elastic elongation and tension meets Hooke’s law, and the elastic elongation of strip produces speed difference. Based on these principles, the tension differential equations were derived for rolling strip with uniform and variant strip sections with one step or n-1 step disturbance points. The simplified forms of these equations are the same as reported in other references.