Abstract: Alloy samples are excited with the radioisotope source and measured by x-ray spectrometer using the fundamental-parameters method without chemical treatment and refernce standared material. The data are processed by the microcomputer-EMG666. The change of the incident angles, the first fluorescent effect,the secondary fluorescent effect and scattering effect are studied. The accuracy and the precision of this method is less than ±3% and ±6%, respectively.