The cupper(II) complexes [Cu(L1)(Bipy)(H2O)2]Cl2.2.5H2O (1), [Cu(L2)(Phen)(H2O)2]Cl2.2.5H2O (2) and [Cu(L3)(Phen)(H2O)2]Cl2.0.5H2O (3) (L1=1-[4-(4-methoxyphenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-5-yl]ethanone, L2=4-Oxo-6-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile, L3=Ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2- methyl-4H-pyran-3-carboxylate, Bipy=2,2\-bipyridine, Phen=1,10-phenanthroline) were done. Elemental analysis, magnetic moment, molar conductance, thermal analysis, infrared spectra, and electronic spectrum investigations were used to describe these complexes. The molar conductance results of complexes indicated that the cupper complexes are electrolyte with 1:2. The FT-IR data showed that L1, L2, L3, Phen, Bipy coordinated with metal ions as bidentate ligands. The magnetic moment of Cu(II) complexes found around (1.71 BM) which indicate the structure of complexes as octahedral geometry. The postulated stereochemistry and subsequently the predicted mechanism of heat degradation were validated by TG and DTG studies. The Horowitz-Metzger (HM) and Coats-Redfern (CR) techniques were used to compute the activation thermodynamic parameters. Thermal decomposition processes of complexes (1), (2) and (3) are non-spontaneous (negative values for ΔS*). In vitro antibacterial properties of the mixed ligand and their complexes were evaluated against several bacterial and fungi strains.