[Purpose/significance]In recent years, knowledge graphs have gained wide attention from academia and industry. Knowledge graphs of different domains are widely used in query understanding, automatic question answering and document representation. [Method/process]In this paper, the construction of vertical knowledge graphs and related applications were studied. Specifically, we first gave a formal definition of knowledge graph. Then a data-driven incremental constructing method was proposed. We put emphasis on constructing a data graph of a vertical knowledge graph. Based on the proposed method, we have built Traditional Chinese Medicine Knowledge Graph, Marine-oriented Knowledge Graph and Security-oriented Knowledge Graph. [Result/conclusion]These vertical knowledge graphs illustrate the feasibility of our method and extensive usability of vertical knowledge graphs.