The rapid progress in medicine provides an increase in both average life span but also increases number of patients who need intensive care throughout the world. The morbidity and mortality of systemic fungal infections have become a serious problem because of suppressed immunity due to chemotherapy or intentional use of suppressants after tissue/organ transplantations. Voriconazole (Vfend, Pfizer) is one of antifungal agent against these fungal infections as a derivative of fluconazole. However some fungi types gain resistance against this agent. In this project, we use budding yeast Saccharomyces cerevisiae as a model organism to identify the genes that cause resistance Voriconazole by performing a genome wide screening. MRS3 and TRI1 genes were determined as resistant genes against lethal dose of Voriconazole. Their overexpression exhibited resistance to Voriconazole and also Ketoconazole in cross-resistance test. According to real-time PCR results, both MRS3 and TRI genes showed overexpression in IC50 of Voriconazole treatment when compare with their untreated status. Microaaray analysis indicated the expression change of our resistant genes is not more than 2 fold. In addition to expression analysis, functional analysis such as membrane dynamics tests have salt (NaCl, LiCl) and cationic drug (HygB,spermine,TMA) tolerance, membrane potential, volume/size measurements and cytoplasmic pH values were analyzed to reveal the mechanisms of resistance. Our results showed that no linkage between Variconozole resistance provided by MSR3 and TRI1 genes and functional analyses mentioned above.