Four kinds of butyl alcohols were alkylated by dialkyl sulfates at 4045°C to prepare alkyl butyl ethers using phase transfer catalysts. Experiments were carried aut for pursuing the optimum reaction conditions in the presence of tetrabutylammonium salt, which proved to be most effective among the catalysts tested. It has been found that alkyl n-butyl and isobutyl ethers can be obtained in good yields over 93%, but alkyl s-butyl ethers in about 50% and alkyl t-butyl ethers only in less than 20%.