Antibacterial activity of picisan leaves extract was tested against Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella Typhi by well diffusion method. Picisan leaves was extracted by maceration method and three different solvent (ethanol, ethyl acetate, and hexane). Extraction was performed 48 for hour in room temperature. Picisan leaves extract were diluted into five concentration (5%, 10%, 15%, / 20%, and 25%) by each solvent. The identified phytochemical compounds in picisan leaves extract were alkaloid, saponin, tannin, phenolic, flavonoid, steroid, and glycoside. Only Gram positive bacteria that was inhibited by the extract with ethanol as the solvent and produce > 6 mm inhibitin zone with in 15% concentration. Therefore, ethanol and 15% was selected solvent and selected concentration. The treatment of pH and heating temperature affected the stability of picisan leaves extract. Extract with treatment at lower pH, high temperature, and longer heating has better inhibition capability than extract without treatment. However, the extract has lower inhibition capability than penicillin G and stretptomycin in the concentrations of 10 ppm. Picisan leaves extract inhibit bacterial by destroy their cell wall and caused leakage of ion Cat' (6.6 — 11.97 mg/L) and ion K+ (2468.30 — 2606.05 mg/L). The result of GC-MS testing show that seven compounds of the highest in picisan leaves extract are /3-sitosterol, vitamin E, phytol, campesterol, palmitic acid, linolenic acid, and nonanoic acid.