In situ x-ray diffraction experiments on iron at pressures of 22--32 GPa and temperatures of 300--1500 K were carried out using an MA8-type high-pressure apparatus, employing sintered diamond anvils, combined with synchrotron radiation. No phases other than ϵ(hcp) and &ggr;(fcc) were observed in this pressure and temperature range. It became clear that non-hydrostaticity or chemical reaction with hydrogen causes serious problems in high-pressure and high-temperature x-ray diffraction study on iron. The average thermal expansivity of ϵ phase between 300 K and 1000 K and the zero-pressure bulk modulus of &ggr; phase at 1400 K were determined by assuming that no chemical reaction occurred in the present study. The thermal expansivities of ϵ iron at 22 GPa and 32 GPa are determined to be 3.88¿10-5 K-1 and 3.16¿10-5 K-1, respectively. In this case, the volume at 22--32 GPa and room temperature is about 1% larger than the literature value. The bulk modulus of &ggr; iron is determined to be 120 GPa, when its pressure derivative is fixed at 5.