A method and a device for scrambling sequence configuration, a user equipment and a base station are provided. The method includes: obtaining a search space and/or a transmission mode corresponding to an enhanced control channel; performing a scrambling initialization operation according to the search space and/or the transmission mode, and determining an initialization value of a scrambling sequence; determining the scrambling sequence according to the initialization value of the scrambling sequence; and scrambling a transmission signal transmitted by the enhanced control channel according to the scrambling sequence and then transmitting, so that a user equipment which receives the transmission signal performs a descrambling operation according to the scrambling sequence in the transmission signal. Randomization of interferences between different cells or terminals can be guaranteed as far as possible.