Abstract: It is found that the fine structure constant α＝ｅ２/ｃ is alterable rather than a constant.It’s a puzzle which one of the three quantities ｅ，，ｃ leads to the change of α.The result α≈１/１３７．３１３ can get from Dirac large number D,Plank mass mPl and Planck large number A while using the rest mass of electron,accord with habitual value  α≈１/１３７．０３６  well.Whereas under kinetic condition,the quantity of electricity of electron e will increase along with the mass of electron,as well as the fine structure constant is changable.According to the sub-quark model,‘abnormal masses,‘abnormal charge’ and ‘abnormal magnetic torque’ effects will be present with leptons.The calculated ‘abnormal magnetic torque’ which coherent with ‘abnormal charge’ accorded with experimental value well.Thus we can take the change of electron charge for the result of ‘abnormal charge’.

Key words: fine structure constant, Dirac large number, Plank mass, &lsquo, abnormal charge&rsquo, &lsquo, abnormal magnetic torque&rsquo