This paper shows the characterization of a 730 MW{sub th} bituminous coal fired utility boiler with regard to the combustion behavior of a medium and a high volatile bituminous coal. The boiler commissioned in 1997 has a Steinmueller-T-firing system equipped with internally air-staged low-NO{sub x} burners. Extensive measurements were carried out in the burner near field of the boiler and in the burn-out zone above the over fire air injection. particle velocities and temperatures of particle clouds were measured with newly developed probes using non-intrusive techniques: 2-dimensional laser Doppler Anemometry for velocities and Quotient Pyrometry for temperatures of particle clouds. Gas composition (O{sub 2}, CO, CO{sub 2} and NO) and temperature were determined with conventional suction probes. Simultaneously to the measurements, numerical simulations were carried out with the 3-dimensional furnace-simulation-code AIOLOS, and in-house development of the Institute of Process Engineering and Power Plant Technology (IVD). Gas concentration, temperature and velocity distribution in the boiler were calculated with a discretization of 2,300,000 grid points. The combination of measured data and predicted results enables a comprehensive characterization of the bituminous coal fired utility boiler.