The interactions of cobalt sulphate and nickel acetate with ofloxacin (ofo, I), a 4-quinoline derivative, were studied. The hydrothermal technique was adopted in this work. The isolated solid complexes were characterized by elemental analysis, infrared spectra, electronic spectra, fluorescence spectra and thermal analysis. The results support the formation of complexes of the formula Co(ofo)2 x 4H2O (II) and Ni(ofo)2 x 4H2O (III). The infrared spectra of the isolated solid complexes suggested that ofo acts as bidentate ligands through one of the oxygen atoms of the carboxylic group and the ring carbonyl oxygen atom. Thermogravimetric (TG) and its differential (DTG) were carried out for the complexes. The data obtained indicated that the thermal decomposition of the two complexes in inert atmosphere proceeded approximately with two main degradation steps. I showed a intense fluorescence in solid state at lamda(ex)/lamda(em) = 365 nm/461 nm, and two complexes displayed weakly similar emission maximum at 470 nm in the powder samples at ambient temperature, while the emission of II and III may be mainly originated from the intraligand excited states of I. I, II and III were assayed against two kinds of gram-positive and two kinds of gram-negative bacteria by in vitro doubling dilutions method. The results indicated that II and III have the similar minimal inhibitory concentration (MIC) as the I against S. Aureus, M. Lutens, E. Coli and P. Aeruginosa. The inhibitory effect of I, II and III on leukemia HL-60 cell line has been measured by using MTT (Methyl-Thiazol-Tetrozolium) method and that on liver cancer BEL-7402 cell line measured by SRB (Sulphurhodamin B) method. The results indicated that the complexes in the high concentration have inhibitory effect on HL-60 cell line.