1. A method of recommending a dialogue sticker based on situation and preference information, comprising: by a server connected to a first user terminal and a second user terminal through a network, analyzing utterances between the first user terminal and the second user terminal and selecting a sticker candidate group to be recommended to the first user terminal; calculating an expression suitability based on the preference and situation information in regard to the selected sticker candidate group; and determining the ranking of stickers in the order of suitability and then recommending a higher ranked sticker to the first user terminal.