The paper first examines the citation of software in Chinese core journal papers on knowledge mapping using a content analysis approach, and then explores the diffusion characteristics of the top ten most frequently used knowledge mapping software tools with several diffusion indicators such as diffusion breadth and diffusion speed. The findings are as follows:（1）Knowledge mapping research increasingly relies on software and the proportion of papers about knowledge mapping using software is more than 90% up to 2017. However, the state of software citation practice does not become better and the uncitedness of software in domestic knowledge mapping research is still noticeable.（2）The speed of new software acceptance and usage of Chinese researchers in the field of knowledge mapping is increasing.（3）The knowledge mapping software tools have been adopted slowly in early years, but afterward the diffusion speed grows rapidly up to now.（4）The knowledge mapping software tools have occurred earlier in the fields of library, information and document science, management, journalism and communication, and computer science. And they have been more frequently used in the research of library, information and document science, education and management.