tSiOC and SiZrOC ceramics were obtained starting from the hydrosilane system without and with zirco-nium n-propoxide (Zr(OnPr)4) by sol–gel route. The precursor architectures indicated that the presenceof Si H bonds leads to a different cross-linking mechanism of SiZrOC precursor, where the Si H bondswere involved in the formation of Si O Zr bonds. The presence of Zr caused a lower content of sp3carbonin SiZrOC ceramics. At above 1400◦C, the sp3-C/Si ratio in both ceramics increased due to carbothermalreduction, especially rapidly for SiOC ceramics, suggesting the carbothermal reduction in SiZrOC ceramicshas been strongly suppressed with the presence of ZrO2. Raman spectroscopy showed the graphitiza-tion degree of free carbon increased with temperature in both ceramics, but was always lower in SiZrOCceramics. The SiZrOC ceramics has been found to exhibit remarkably high temperature stability withrespect to carbothermal decomposition up to 1600◦C in comparison with the SiOC ceramics.