**7. Conclusions**

This paper presents a bibliometric analysis of *Symmetry* from 2009 to 2019 based on WoS. According to VOSviewer and CiteSpace, the analyses are conducted from the following aspects: basic characteristics, including the publications, citation number and citation structure; the influential objects; co-citation contributors and the burst detection analyses; the author-keywords co-occurrence analyses and timeline view analysis. The number of publications has almost increased every year since 2014. The year 2019 was the year with the largest volume of publications and 2018 was the year with the most citations. China is the most productive and influential country. The top three productive institutions are China Medical University Taiwan (China), National University of Defense Technology China (China), and Beijing Jiaotong University (China), respectively. The prominent author is Smarandache F. According to the results, cooperation among contributors also plays a key role in the publications. In the view of author-keyword analyses, the scopes of *Symmetry* are constantly enriching and no longer limited to the symmetry phenomena in the fields of physics and chemistry. At present, these include decision making, fuzzy mathematics, deep learning, machine learning and classification, etc. We also discuss possible reasons for this and future development.

In summary, this paper is a relatively comprehensive view of *Symmetry* by bibliometric analysis, which helps scholars understand its current status, future trends of development, and research scope. In future, we will continue to collect its productions and pay more attention to its developments, aiming to make the conclusions richer.

**Author Contributions:** Conceptualization, Z.X.; data curation, J.A.; formal analysis, Z.T.; investigation, B.L.; methodology, Z.X.; project administration, Z.X.; supervision, E.K.Z; validation, E.K.Z.; writing—original draft, B.L.; writing—review and editing, J.A. and Z.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was funded by the National Natural Science Foundation of China under Grant 71771155. **Conflicts of Interest:** The authors declare no conflict of interest.
