Purpose: This study was examined the characteristics of bacteria isolated from the dental stone that is made ??in the dental laboratory. Methods: 104 dental stones samples were collected from the 4 dental laboratory. Characteristics of bacteria were investigated by microorganism isolation culture method using a Blood Tryptic Soy Agar(TSA) medium. Results: The detected various bacteria was confirmed as pathogenic bacteria, non-pathogenic bacteria and natural bacteria. The isolated bacterial number was confirmed $2.9{ imes}10^3CFU$ and maxium bacterial number of $3.0{ imes}10^4CFU$. Conclusion: Therefore, infection prevention education is required, it must be to live up the hand-washing and wear protective clothing to protect themselves when working in a dental laboratory.