The effects of alcohol treatment on the activity and loading amount of Candida rugosa lipase (CRL), Candida Antarctica lipase B (CALB) and Porcine Pancreas lipase (PPL) immobilized on methyl-modified silica aerogels were investigated, and the fluorescent analysis was used to explore the change of lipase hydrophobicity in aqueous solution caused by alcohols. It is found that alcohol types and the stages at which alcohol was added significantly influenced the performance of immobilized lipases through changing the hydrophobicity of the molecules. For CRL and PPL, five kinds of alcohol were added in the adsorption process, and n-butanol and isopropanol improved the apparent activity of CRL and PPL up to 2.5 times and 2 times those of the untreated ones, respectively; however, for CALB, it is better to activate the immobilized CALB after the adsorption process, and the apparent activity of CALB increased up to 2.76 times through n-butanol treatment. (C) 2010 Elsevier Ltd. All rights reserved.