In recent years the growth of data journalism researches formed a huge phenomenon in Journalism and communications. The increasing emphasizing on data and visualization both in medias and universities indicate data journalism are becoming a professional field. On the one hand，due to the changes in the process of production and presentation，especially the emphasis on technical elements，data journalism has close relation with practice，but lacking of theoretical concerns. On the other hand，even though the numbers of researches are quickly increasing，there are many ambiguities and disputes in it. The concepts and categories of the data journalism needs to be clarified. Therefore，based on literature review，this paper discuss the concepts，categories，and the professionalism of the data journalism in order to provide a reference with theoretical perspective.