A composition utilizing natural materials is selected from a group of plant extract comprising: Taiwan cypress, stout camphor tree, Taiwan incense cedar, Cinnamomum camphora, Cymbopogon nardus, Litsea cubeba, Cinnamomum zeylanicum, Taiwan Cunninghamia lanceolatavar, Melaleuca alternifolia, Eucalyptus robusta smith, Cryptomeria japonica and Acacia confuse. The tumor cell-inhibited composition having the efficiency of inhibiting the growth of tumor cells is formed by mixing these extracts based on a specific ratio.