Methods, systems and programming for providing query suggestions based on user's previous search query. In one example, an input including a prefix of a first query is received from a user in a user session. At least a second query that was previously received from the user in the user session is then obtained. A third query is obtained based on the second query and the prefix of the first query. One or more query suggestions are provided to the user as a response to the input. The one or more query suggestions include the third query.