Background: Bacterial ocular infection is a common problem.[1;6]. Microbiological investigation of the conjunctival swab is one of the broadly used method to study etiological agent of conjunctivitis[2]. Microbial culture techniques have shown that 80% of conjunctival swabs yield cultivable microbes.[3]. Conjunctival sac contains variety of pathogenic and non-pathogenic microbes. Normal microbes play a protective immunological role in preventing the proliferation of pathogenic species that can cause ocular infections whereas pathogenic microbes contribute to infectious and autoimmune diseases of the eye. [4;5] Purpose: To investigate common microbes detected by conjunctival swab analysis and their antibiotic sensitivity. Methods: In our descriptive study, 264 conjunctival swab samples that had been analyzed by MALDI-TOF technology using VITEX MS at Gyals Medical Center from July 2019 to November 2020 were evaluated. Results: Cultivable microbes and fungus were detected in 71.56% of overall swabs. 28.44% were non cultivable. Fungus and 43 different types of microbes were found. 35% of all microbes were Staphylococcus including Methicillin -resistant Staphylococcus aureus, Staphylococcus aureus, Staphylococcus epidermidis. 28% of microbes were Streptococcus including Streptococcus mitis, Streptococcus pneumoniae, Streptococcus anginosus, Streptococcus parasanguinis, Streptococcus agalactiae, Streptococcus pyogenes, Streptococcus salivarius, Streptococcus spp. 20% of all microbes were miscellaneous bacterium including Enterococcus, Corynebacterium, Klebsiella, Acinetobacter, Escherichia, Candida parapsilosis and the remaining are others. Staphylococcus aureus is sensitive to Quinupristin/Dalfopristin, Linezolid, Vancomycin, Tigecycline, Nitrofurantoin whereas they are resistant to Benzylpenicillin, Ciprofloxacin, Amoxicillin, Amoxicillin/ Clavulanic Acid, Cefazolin that are widely used in Mongolia. Conclusion In 76.71% of overall conjunctival swab samples were found cultivable microbes. Methicillin -resistant Staphylococcus aureus, Staphylococcus aureus, Staphylococcus epidermidis are the most common microbes detected by conjunctival swab analysis. The common microbes are resistant to Benzylpenicillin, Ciprofloxacin, Amoxicillin, Amoxicillin/Clavulanic Acid, whereas they are sensitive to Quinupristin/Dalfopristin, Linezolid, Vancomycin, Tigecycline, Nitrofurantoin, Erythromycin, Clindamycin.