Solvent- free thermal heating, one-pot condensation of acetophenone, ethyl cyanoacetate or malononitrle and substituted Aromatic aldehyde, ammonium acetate give, 2oxo-3-cyano-4-substituted Aryl-6-phenyl pyridine [I]a-h , or  2-amino-3-cyano-4-substituted Aryl-6-phenyl pyridine derivatives[II]a-f , respectively.              Treatment of compounds 2-oxo-3-cyano-4-substituted Aryl-6-phenyl pyridine with phosphorous penta sulphide (P2S5), give 2-thioxo-3-cyano-4-substituted Aryl-6-phenyl pyridine derivatives[III]a-c .             All prepared compounds are characterized by, C.H.N.S-elmental analysis, melting points, FTIR-and1H-NMR-spectral analysis .              Antibacterial examination of synthesized compounds [I]a-c , [II]a-c  and  [III]a-c against five types of, (G-) and (G+) bacterial  . in  comparison with common  antibiotic like  Ampicillin, Amoxicilin and Lincomycin the result shows 2-thioxo-3-cyano-4-substituted Aryl-6-phenyl pyridine derivatives are more reactive than 2-oxo-3-cyano pyridine derivatives or 2-amino-3-cyano pyridine derivatives .