Abstract: Using the three dimensional and paralleled JMCT Monte Carlo code, the backscattered photoelectric yields and electron energy spectra are calculated for the cases that black body X-ray sources of temperatures of 1, 3, 5, 8 keV impact on the material surfaces of Al, SiO₂ and Au respectively. The simulation results are consistent with the results in references, which verify the validity of the code. Then the typical photon-electron transport example in SGEMP for black body X-rays impacting on a cylinder cavity is calculated. Half of the side-face of the cylinder emits photoelectrons in the case that the black body X-rays of temperature 1 keV and fluence 1 J/m² impact on the side-face of the cylinder. The photoelectron parameters of photoelectric yield, energy distribution and angular distribution related with azimuth are calculated. The results show that obliquely incident X-ray could induce higher photoelectric yields than normally incident X-ray and the distributions of photoelectrons are all very close to cosine distribution.