The work aims to improve corrosion resistance of 304 stainless steel surface. With 304 stainless steel as substrate and aluminum isopropoxide as precursor, Al2O3 sol was prepared in the sol-gel method. Xerogel powder was subject to phase analysis with XRD, and corrosion resistance of the ceramic coating was studied, effects of raw materials ratio, amount of peptizer and different sintering temperature on surface morphology and corrosion resistance of the ceramic coating were determined. The sol as-prepared was stirred provided with ratio of ethanol to deionized water of 1:1:100, water bath temperature of 70 ℃ and pH of 4~5. A crack-free ceramic coating featuring in uniformity, high purity and good surface quality could be prepared after thermal insulation at 600 ℃ for 30 min. Ceramic coating was composed of high purity Al2O3. The ceramic coating exhibits excellent corrosion resistance in NaCl solution and salt fog.