The Ni(II) biosorption characteristics of Pseudomonas fluorescens biomass was examined as a function of initial pH, contact time and initial metal ion concentration. The pseudo-second-order kinetic model was found to be well suited for the entire adsorption process of Ni(II) on biomass. Adsorption equilibrium studies showed that Ni(II) adsorption data followed the Langmuir model, the maximum binding capacity of Ni(II) was 84.45 mg/g at pH 7.0 , shaker speed 150 rpm, at 27 °C. FTIR spectra showed that the principal functional sites taking part in the sorption process included carboxyl , hydroxyl groups and -CH3 stretching groups, the mechanism analysis showed that the chemical chelating was the main adsorption form, electrostatic attraction hydrogen bonding in the process of adsorption. The present study indicated that Pseudomonas fluorescens biomass may be used as an inexpensive, effective and easily cultivable biosorbent for the removal of Ni(II) ions from environmental and industrial wastewater.