The present investigation was carried to determine the phytochemicals of Sargassum linearifolium (Turner) C.Ag using UV-Visible spectroscopy, FTIR spectroscopy and HPLC. The UV-Visible spectrum of chloroform extract of Sargassum linearifolium (Turner) C.Ag. showed the peaks at the nm of 325, 412, 537, 610, 668, 882, 962, 1015 and 1059 with the absorption 1.573, 2.783, 0.593, 0.502, 1.150, 0.181, 0.108, 0.099 and 0.030 respectively. The FTIR spectrum was revealed the presence of amides, aliphatic nitro compounds, organo phosphorus compounds, ether, amines, aromatic nitro compounds, benzene ring in aromatic compound, aromatic nitro compound, primary amines, aldehyde, aliphatic compound and primary amides in chloroform extract of Sargassum linearifolium. The qualitative HPLC fingerprint profile displayed thirteen compounds at different retention times. The profile displayed seven prominent peaks at the retention times of 1.637min, 2.360min, 2.670min, 2.803min, 3.017min, 3.267min and 3.433min followed by six moderate peaks at the retention time of 4.003min, 4.293min, 5.970min, 7.210min, 8.673min and 9.773min.