Phytochemicals are chemical compounds often referred to as secondary metabolites. Thirty nine bioactive phytochemical compounds were identified in the methanolic extract of Cinnamon bark. The identification of phytochemical compounds is based on the peak area, retention time molecular weight and molecular formula. GC-MS analysis of Cinnamomum zeylanicum revealed the existence of the 6 -Oxa-bicyclo[3.1.0]hexan-3-one, Benzaldehyde, Cyclohexene,4-isopropenyl-1-methoxymethoxymethyl, Benzoic acid- methyl ester, Benzaldehyde dimethyl acetal, Benzenepropanal, Benzylidenemalonaldehyde, 3-Phenylpropanol, Cinnamaldehyde, (E), 2-Propen- 1- ol,3-phenyl, 9-Methoxybicyclo[6.1.0]nona - 2,4,6- triene, 1,3-Bis(cinnamoyloxymethyl) adamantine, Alfa.- Copaene, Naphthalene, 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methyl), Cis - 2-Methoxycinnamic acid, Bicyclo[3.1.1]hept-2-ene,2,6- dimethyl-6-(4-methyl-3-pentenyl), Trans-2-Hydroxycinnamic acid, methyl ester, y-Muurolene, ?-Guaiene, Cadala-1(10),3,8-triene, Isolongifolene,4,5,9,10-dehydro, Cubenol, Tau-Muurolol, ?-Cadinol, Spiro[tricyclo[4.4.0.0(5.9)] decane-10.2oxirane],1-methyl-4-isoprol, 6-Isopropenyl-4,8q-dimethyl-1,2,3,5,6,7,8,8a-octahydronaphthalen, Ethyl9,9-difomylnona-2,4,6,8-tetraenoate, Trans-13-Octadecenoic acid, Tributyl acetylcitrate, 9,12,15-Octadecatrienoic acid, 2,3-dihydroxypropyl ester, 9-Octadecenamide, 17.alfa.-21?-28,30-Bisnorhopane, 17.alfa.-21?-28,30-Bisnorhopane, Androstan-3-one,cyclic 1,2-ethanediyl mercaptole, (5?), (4H)4a,5,6,7,8,8a-Hexahydrobenzopyran-5-one-3-carboxamide,2, 4H-Cyclopropa[5?,6?]benz [1?,2?,7,8]azuleno[5,6]oxiren-4-one,8,8a, (22S)-21-Acetoxy-6?,11?dihydroxy-16?,17?-propylmethylenediox, (+)-?-Tocopherol,O-methyl and Stigmasterol. Cinnamomum zeylanicum contain chemical constitutions which may be useful for various herbal formulation as anti-inflammatory, analgesic, antipyretic, cardiac tonic and antiasthamatic. Cinnamomum zeylanicum was highly active against Aspergillus flavus (6.16±0.42). Methanolic extract of bioactive compounds of Cinnamomum zeylanicum was assayed for in vitro antibacterial activity against Pseudomonas aerogenosa, Escherichia coli, Proteus mirabilis, Staphylococcus aureus and Klebsiella pneumonia by using the diffusion method in agar. The zone of inhibition were compared with different standard antibiotics. The diameters of inhibition zones ranged from 6.12±0.52 to 0.39±0.17 mm for all treatments