The invention relates to a liquid chromatogram-tandem mass spectrum method for detecting pitavastatin in human plasma, and application to clinical pharmacokinetic research. The invention provides a method for detecting pitavastatin concentration of plasma. By the method, the pitavastatin concentration of the plasma can be analyzed through LC-MS / MS. According to the method provided by the invention, a protein precipitate pretreatment method is preferably adopted, deuterated pitavastatin serves as internal standard, Eclipse Plus Phenyl-Hexyl column isocratic elution is adopted, and electrospray ionization (ESI) tandem mass spectrum detection is adopted. By adoption of the method provided by the invention, the extraction and recovery rate of the plasma sample is 93 percent or higher and is not influenced by matrix effect, the stability of the pitavastatin is inspected by counting the pitavastatin concentration RSD% before pretreatment, the accuracy of the measured data is guaranteed, the method is high in specificity and selectivity, high in sensitivity, rapid in detection and small in use amount, and simple, reliable, high-flux and condition-controllable clinical mass-batch sample analysis requirements are met. The specificity, the stability and the like of the method provided by the invention are verified, and the method can be used for evaluating the bioequivalence of various dosage forms of pitavastatin successfully.