Abstract: OBJECTIVE To explore the effect of voriconazole on treatment of multiple myeloma patients complicated with invasive fungal infection and its association with polymorphism of CYP2 C19 gene. METHODS Totally 67 multiple myeloma patients complicated with invasive fungal infection who were treated in the First Affiliated Hospital of Henan University of Science and Technology from Jan 2019 to Oct 2020 were recruited as the study objects and were divided into the high metabolism group with 16 cases, the intermediate metabolism group with 32 cases and the low metabolism group with 19 cases. The patients were treated with voriconazole, the therapeutic effect, adverse reactions and pharmacokinetic parameters were observed and compared among the three groups of patients. RESULTS A total of 67 strains of fungi were isolated from 67 patients, 20 of which were Candida albicans, and 18 were Aspergillus fumigatus. The patients with respiratory tract infection（44 cases） were dominant among the patients with fungal infection. The effective rate of treatment with voriconazole was 75.00% in the high metabolism group, 93.75% in the intermediate metabolism group, 100.00% in the low metabolism group; the incidence of adverse reactions was 6.25% in the high metabolism group, 21.88% in the intermediate metabolism group, 47.37% in the low metabolism group; there were significant differences（P＜0.05）. There was no significant difference in the voriconazole dose per kilogram of body weight among the three groups. The median standardized blood concentration of voriconazole, from high to low, were as follows: the metabolism, the intermediate metabolism, the high metabolism, and there was significant difference（P＜0.05）. CONCLUSION The effect of voriconazole is closely associated with the polymorphism of CYP2 C19 gene of the multiple myeloma patients complicated with invasive fungal infection, the genotypes of CYP2 C19 determine the types of metabolism, which may affect the blood concentration of voriconazole, curative effect and adverse reactions. The dosage of voriconazole can be administrated based on the genotypes of CYP2 C19.