The invention relates the method for forecasting the drug-effect. The method measures the polymorphism gene type to forecast the drug-effect of calcium antagonist drug. The method forecasts the drug-effect of calcium antagonist drug by measuring the polymorphism gene type of key enzyme gene on the aminothiopropionic acid metabolism path.; at the mean time, according to the effect, prepare the compound drug which can improve the drug-effect of calcium antagonist by adjusting the preparation of aminothiopropionic acid metabolism path. The invention improves the effective rate of clinical drug therapeutics and the safety of clinical drug, and reduces the drug toxin side effect and cost.