Quaternary compounds Cu2FeSnS4 (CFTS), a promising alternative material for solar cell absorber layer, were successfully synthesised by a liquid reflux method in a mixture solvent of triethylenetetramine-ethylene glycol (TETA-EG, 1:1, v/v) at 230°C for 3 h under the atmospheric pressure condition. The phase, micro-structure, morphology, chemical composition and optical properties of the as-synthesised CFTS micro/nano particles were characterised using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry and ultraviolet-visible absorption spectrophotometer. The results showed that the stannite structured CFTS micro/nano particles with close to theoretical stoichiometric ratio were pure and well-crystallised, the particle size ranged from 70 to 240 nm and the particles were well-distributed, the band gap was about 1.25 eV which indicated its suitable application as the absorption layer of thin film solar cells.