1. A method using a processor for user-centered information search, the method comprising: receiving a search request; determining, by the processor, a first object of the search request by using keyword information of the search request and generating one or more first properties which are related to the first object, the first object and the one or more first properties comprising a classification unit of an information search structure, wherein the first object and the one or more first properties are expressed by the keyword information of the search request; determining, by the processor, one or more second objects and one or more second properties corresponding to the one or more second objects, the one or more second objects being related to the one or more first properties, wherein a class is generated to define one or more objects; and providing a search result corresponding to the search request by using at least one of the first object, the one or more first properties corresponding to the first object and the one or more second objects corresponding to the one or more first properties, the one or more second properties corresponding to the one or more second objects, and, the class comprising a group.