The 2nd abstract of my paper, I'll submit it tomorrow. Thanks! Abstract To save cost of sampling for estimating the area under the amlodipine plasma concentration versus time curve in 24 hours (AUC0-24). Limited-sampling strategy models (LSS) was developed and validated by mutilple regression model within 4 or fewer amlodipine concentration values. Absolute prediction error(APE), root of mean square error(RMSE) and visual predict check were used as criterion. The results of Jackkinife validation shows there are fifteen (9.4%) of the 160 LSS based on regression analysis were not within an APE of 15% by using one concentration-time point. 156 (97.5%), 159 (99.4%) and 160 (100%) of the 160 LSS model were capable of predicting within an APE 15% by using 2, 3, 4 points, respectively. Limited sampling strategies were developed and validated for estimating AUC0-24 of amlodipine. The present study indicated that the implemention of both 5 mg and 10 mg dosage were enabled accurate predictions of AUC0-24 by the same LSS model. This study shows 12, 4, 24, 2h after administration are key sampling time. The combination of (12, 4), (12, 4, 24) or (12, 4, 24, 2h) might be choice as sampling hours for predicting AUC0-24 in practical application according to requirement.