Therapeutic drug monitoring (TDM) for busulfan (BU) is currently performed by multiple plasma sampling. Saliva is considered a noninvasive TDM matrix. This study aimed to investigate intravenous BU pharmacokinetics (PK) in plasma and saliva, and establish a limited sampling strategy (LSS) for predicting the area under the concentration-time curve from 0 to infinity in plasma (AUC 0-∞,p) by using saliva samples. Therefore, the PK of BU was studied in thirty-seven Chinese patients. Pearson correlation analysis was used to evaluate the correlation between the AUC of BU in plasma and saliva. LSS models were established by the multiple linear regression analysis. The prediction error, the mean prediction error, and the root mean square error were used to evaluate the predictive accuracy. The agreement between the predicted and observed AUC 0-∞ in saliva was investigated by the intraclass correlation coefficient (ICC) and Bland-Altman analysis. The accuracy and robustness of the models were evaluated by using the bootstrap procedure. The result of PK analysis 62.2% of patients (23/37) was within the target range of AUC 0-∞,p . A good correlation between saliva and plasma BU AUC 0-∞ was observed (r = 0.63, P<0.01). The bias and precision of the model 7 and model 13 were less than 15%. The ICC exceeded 0.9, and the limits of agreement were within ±15%. The two-point LSS model in saliva is a convenient and desirable approach to predict the AUC 0-∞ of four times daily intravenous BU in plasma, which can be used to design personalized dosing for BU. This article is protected by copyright. All rights reserved.