In sample preparation and mass spectrometry analysis, sample dissolution, column chemistry, concentration mismatches, and matrix effects have significant potential for introducing ana-lytical artifacts during Mg isotope analysis. Based on the low MgO content and undesirable matrix el-ements in felsic rocks, the development of well-characterized felsic standards is essential to reduce in-terlaboratory mass bias, enable the assessment of data accuracy, and facilitate the comparison of chemical separation procedures in different laboratories. In this work, the homogeneity and long-term stability of two felsic rock standards, GSR-1 and RGM-2, were evaluated due to their low MgO con-tents. Furthermore, synthetic solutions with doped matrix elements were used to evaluate potential Mg isotope analytical artifacts using multi-collector inductively coupled plasma mass spectrometry. The accuracy and precision of Mg isotopic compositions in GSR-1 and RGM-2 were assessed by repeated measurements over twelve months. The long-term tests show that the Mg isotopic compositions of the two low MgO felsic rocks (GSR-1 and RGM-2) are homogenous among batches and can be used as low MgO reference materials for accuracy assessments of Mg isotopic analyses. The Mg isotopic composi-tions (δ26Mg) of GSR-1 and RGM-2 were marked as -0.223‰±0.053‰ (2s, n=50) and -0.184‰±0.058‰ (2s, n=50) respectively.