Abstract: Objective To evaluate 9 389 cases of therapeutic drug monitoring (TDM) and the clinical drug usage of cyclosporine A(CsA) in Guangdong Provincial People's Hospital during January 2014 to December 2017. Methods Analysis and statistics of CsA TDM data of 9 389 cases (1 719 subjects) in Guangdong Provincial People's Hospital were carried out. The effects of gender, age, liver function and changes of combined medication on the blood concentration of CsA in 501 patients with hematological disease were analyzed. Results Among all the first TDM concentration, only 30.8% was within the therapeutic window. Constituent ratio of patients whose drug concentrations were monitored once, twice, three times or more than ten times respectively of 41.0%, 16.9%, 9.2 % and 14.4%. Among all the subjects undergoing 3~5 times of TDM, constituent ratio of patients whose drug concentrations of the first, second, third, fourth and fifth monitoring were within the therapeutic window accounted for 38.8%, 38.9%, 39.2%, 37.1% and 47.1% respectively. Gender, liver function, and changes of combined medication had significant effect on the blood concentration of CsA(P<0.05), and age had no significant effect on the blood concentration of CsA(P>0.05). Conclusion Although TDM was widely used, the TDM times were insufficient. Even TDM was multiple, the status of which was not satisfactory. We should pay much more attention to the phenomenon that the patients'medication was not adjusted properly. It may correlate with the individual difference of pharmacokinetic parameters of CsA, and many factors that can affect the concentration of CsA.