Bacteroiospermia is a frequently finding in fresh raw and extended porcine semen and can results in detrimental effects on semen quality and longevity. This study aims to evaluate the type of bacterial contaminants in raw and extended porcine semen and the reducing effect of antibiotic test. To investigate bacterial contaminants, out of 387 sample (raw semen 201, extended semen 186) were collected from 6 artifical insemination centers in Gyeongsangnam-do, were inoculated onto blood agar and MacKonkey agar, respectively. Bacterial colonies were selected after culturing for 48 hours, at $37^{circ}C$, followed by Gram staining, KOH test, oxidase test, catalase test and eventually identified using VITEK System. Total 15 genus and 24 species of bacteria were isolated from these semen samlpes. In raw semen, the most prevalent contaminants were Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Staphylococcus auricularis, Delftia acidovorans, Acinetobacter lowffii, S. aureus and others. And in extended porcine semen, A. lowffii, S. aureus, S. auricularis and other bacteria were identified. Most of them was G(-), which is nonpathogenic bacteria. It seems that bacterial contaminants in fresh raw and extended porcine semen originated from multiple sources at the farms/stud, and were from animal origin and non-animal origins. Whereas, the 7 virus which is known to be detected in porcine semen in 75 cases was not detected. This results showed that removal of bacterial contamination in raw and extended porcine semen is essential and farms were kept for biosecurity and individual hygienes.