Abstract: Uranium enrichment is recognized as a significant target of verification in nuclear safeguards. A method for uranium enrichment determination by analyzing gamma peaks of ²³⁵U, ²³⁸U and ²²⁸Th (daughter of ²³²U) to calibrate relative detection efficiency was described. A code to verify the method by analyzing the spectrum was written. A HPGe detector was used to measure two types of uranium samples with enrichment ranging from 1.8% to 90.2% repeatedly. For the samples measured, the uranium enrichments are determined with an accuracy of about 3%.