The tert-butylation of phenol was investigated over various zeolite catalysts using tert-butyl alcohol as alkylating agent in a down-flow tubular reactor at atmospheric pressure. Zeolite HY was beneficial to the reaction. The important variables affecting the activity and selectivity of zeolite HY, such as reaction temperature, space velocity and molar ratios of tert-butyl alcohol to phenol, were studied. Zeolite HY hydrothermally treated at high temperatures (above 873 K) was unfavorable to the reaction. The activity and selectivity of zeolite HY were not sensitive to its crystallite diameter change. In the alkylation of phenol with tert-butyl alcohol over zeolite HY catalyst, the suitable reaction temperature range was from 398 to 438 K. Lower reactant molar ratios were beneficial top-TBP and o-TBP, while higher ones were helpful to produce 2,4-DTBP. Lower space velocities (WHSV (h(-1))), i.e. <1.66 (based on phenol) were beneficial to the reaction. The present study shows that zeolite HY has a potential application in the production of tert-butyl phenols with high activity and 2,4-DTBP selectivity.