Abstract: In this study 28 Indonesian medicinal plants species has been screened as potential Tumor Necrosis Factor (TNF)-α inhibitor. Plant materials were extracted with methanol. The activity test was performed on human monocyte-derived THP-1 (ATCC No. TIB 202) which was stimulated by Lipopolyssacharide (LPS). The TNF-α production and cell viability were determined by commercial ELISA kit and WST-1, respectively. All extracts were determined for their phenolic, flavonoid and tannin contents by spectrophotometry and chromatography methods. From 40 plant materials, 5 plant materials had cell viability lower than 70% at 10 ppm concentration and about 8 plant materials had good cell viability higher than 90% at 10 ppm concentration. Among 8 plant materials extract which had good cell viability, only Avicenia sp. stem and Goniothalamus macrophyllus leaf methanol extracts had high TNF-α inhibitory activity. The total phenolic, flavonoid and tannin contents were varied depending on the sample. No correlation was found between TNF-α inhibitory activity with the total phenolic content, flavonoid content and tannin content. In conclusion, among Indonesian medicinal plants, the highest potential as TNF-α inhibitors were Avicenia sp. stem and G. macrophyllus leaves.