Abstract: Pulp necrosis is a condition that indicates death of the pulp. Bacteria identified from necrotic root canals were 7 (seven) types of bacteria, namely Acinetobacter calcoaceticus, P.aeruginosa, Staphylococcus aureus, Proteus vulgaris, K. pneumoniae, Actinomyces spp, and Streptococcus spp. Root Canal Treatment (PSA) is an endodontic treatment by removing pulp tissue from infected pulp chambers and root canals. One of the commonly used irrigation ingredients is sodium hypochlorite (NaOCl) solution. This solution has the advantage of being a high level desinfectants because it is very active in all bacteria, viruses, fungi, parasites and some spores and has an effective bactericidal effect on gram-positive bacteria and gram-negative bacteria. Ant nest (Myrmecodia pendans) can be used as an alternative medicine because flavonoids act directly as antibiotics by interfering with the function of bacterial or viral microorganisms. Objective: To determine the effect of antibacterial power between ants (Myrmecodia pendans) extract special to Papua concentration of 15%, 25%, and 50% with 2.5% sodium hypochlorite on Staphylococcus aureus bacteria. Research design: In Vitro laboratory experimental type with agar well diffusion method on TSA media. Calculation of antibacterial power by measuring the radical zone using a sliding caliper. Data were analyzed using the One Way Anova test followed by the LSD (Least Significan Different). test. The results of the study: there are antibacterial effects between Papua special extracts of ants (Myrmecodia pendans) with a concentration of 15%, 25%, and 50% with 2.5% sodium hypochlorite on Staphylococcus aureus bacteria, Papua special extracts of ants (Myrmecodia pendans) with concentration of 50% a shows that the antibacterial power given is highest compared to other treatments.