Activity test of bioactive material of Salung leaf (Psychotria viridiflora Reinw. ex. Blume) against Salmonella thypi in vitro and in vivo has been carried out. Bioactive material was obtained from the maceration and followed by fractionation of liquid-liquid fractionation. Antibacterial activity test performed in vitro to determine the value of the minimum inhibitory concentration (MIC) and in vivo to determine the ability of bioactive cure diarrhea in in rats (Rattus norvegicus) infected by Salmonella typhi. Treatment of bioactive material given is 0, 10, 50 and 100 mg kg-1 of weight. The results showed that the MIC of salung leaf’s bioactive material to Salmonella typhi was 250 μg mL-1. Bioactive ingredient at dose of 10 and 50 mg kg-1 were able to decrease the number of bacterial colonies to 4.14x106 cfu g-1 and 5.4x105 cfu g-1, less than 5.04x106 cfu g-1 as control. Bioactive material in weight of 100 mg kg-1 of weight could reduce the population of Salmonella typhi to zero after 12 days of treatment. The ability to reduce the amount of bacterial colonies of the bioactive material 100 mg kg-1 of weight is equal to the ability of positive control chloramphenicol 10 mg kg-1 of weight.Telah dilakukan uji aktivitas bahan bioaktif dari daun Salung (Psychotria viridiflora Reinw. ex. Blume) terhadap bakteri Salmonella thypi secara in vitro dan in vivo. Bahan bioaktif diperoleh dari proses maserasi dan dilanjutkan dengan fraksinasi secara fraksinasi cair-cair (FCC), Pengujian aktivitas antibakteri dilakukan secara in vitro untuk menentuan nilai konsentrasi hambat minimum (KHM) dan pengujian secara in vivo pada tikus putih (Rattus norvegicus) untuk mengetahui kemampuan bioaktif menyembuhkan penyakit diare yang diinfeksi dengan Salmonella typhi. Perlakuan bahan bioaktif yang diberikan 0, 10, 50 dan 100 mg/kgbb. Hasil penelitian menunjukkan bahwa KHM bahan bioaktif dari daun salung terhadap bakteri Salmonella typhi yaitu 250 μg/ml. Bahan bioaktif pada dosis 10 mg/kgbb dan 50 mg/kg mampu menurunkan jumlah koloni bakteri menjadi 4,14x106 dan 5,4x105 cfu/g, lebih sedikit dibanding kontrol 5,04 x 106 cfu/g. Bahan bioaktif 100 mg/kgbb dapat menurunkan populasi bakteri Salmonella typhi sampai nol setelah 12 hari pengobatan. Kemampuan bahan bioaktif 100 mg/kgbb sama dengan kontrol positif kloramfenikol 10 mg/kgbb
