The present invention relate to a novel synergistic composition of lignans exhibiting anticancer activities for breast, cervix, neuroblastoma, colon, liver, lung, mouth, ovary and prostate cancer obtained from the plant extract of Cedrus deodra, said composition comprising of (-)-Matairesinol in the range of 9 to 13% by weight, (-)-Wikstromol in the range of 75 to 79% by weight, Dibenzylbutyrolactol in the range of 7 to 11% by weight, and Unidentified material in the range of 2.6 to 3% by weight; further, the synergistic composition of lignan is used in combination with pharmaceutically acceptable carriers for inhibiting growth of various human cancer cell lines selected from breast, cervix, neuroblastoma, colon, liver, lung, mouth, ovary and prostate tissues.