Objective：To evaluate the cytotoxicity of nano-silica coating with sol-gel process of alumina-based ceramic. Methods：Coating gel after heat treatment was analyzed by infrared spectrum（IR）, with gel without sintered as control. Human gingival fibroblast cells（HGFC） were cultivated with extractions of alumina-based ceramic with or without nano-silica coating. Relative growth rate （RGR） was analyzed with a methyl thiazolyl tetrazolium（MTT） assay. Results：It can be seen from the IR picture that bending vibration absorption kurtosis of Si-OH vanished after heat treatment. No significant difference was observed between alumina-based ceramic with and without nano-silica coating. Cytotoxical grade（CG） was 0 to 1. Conclusion：Heat treatment may reinforce Si-O-Si net structure of coating gel. Nano-silica coating with sol-gel process of alumina-based ceramic had no significant cytotoxicity to HGFC.