Abstract: A hydrothermal modification was made for Hβ zeolite to improve its catalytic stability.As catalyst，the modified zeolite was applied in the synthesis of ethyl tert-butyl ether（ETBE） with alcohol and tert-butyl alcohol as raw materials under atmospheric conditions.Influences of hydrothermal modification conditions on the catalytic activity and selectivity of Hβ were studied.Results showed that suitable modification conditions were as follows：treatment temperature was 600 ℃，treatment time was 2 h，and space velocity was 2.0 h^-1，under those conditions the ETBE yield was 40%.Activity，selectivity，and stability of the modified catalyst were compared with the untreated one and results showed that although the activity and selectivity decreased a little，the life time of the hydrothermal treated Hβ zeolite was significantly increased by 75 h.

Key words: H&beta, zeolite；hydrothermal treatment；ETBE；activity；stability