Sirolimus（SRL）has been widely used to treat vascular anomalies in recent years. The routine therapeutic drug monitoring for SRL is required to ensure efficacy and prevent adverse effects，due to its narrow therapeutic window and large intra- and inter - individual variability in pharmacokinetics. This article reviewed the analytical methods for SRL blood concentration and the comparison studies between different assays，and discussed the target blood concentration range of SRL in vascular anomalies. The analytical methods for determination of SRL include immunoassays and liquid chromatography-based methods. Immunoassays exhibit significant positive bias，compared to chromatography. Liquid chromatography tandem mass spectrometry is regarded as the“gold standard”in most clinical labs. Generally，goal SRL blood concentrations maintain at 5-15 ng/mL or 10-15 ng/mL. However，there are several classifications of vascular anomalies，and treatment of SRL in these diseases is complicated，and no guidelines for the implementation of therapeutic drug monitoring can be adhered. Future investigations are needed to obtain a more high-level evidence- based medical evidence to guide the therapeutic monitoring and individualized medication of SRL