Abstract Inclusive Monte-Carlo samples are indispensable for signal selection and background suppression in many high energy physics experiments. A clear knowledge of the physics processes involved in the samples, including the types of processes and the number of processes in each type, is a great help to investigating signals and backgrounds. To help analysts obtain the physics process information from the truth information of the samples, we develop a physics process analysis program, TopoAna, with C++, ROOT, and LaTeX. The program implements the functionalities of component analysis and signal identification with many kinds of fine, customizable classification and matching algorithms. It tags physics processes in individual events accurately in the output root files, and exports the physics process information at the sample level clearly to the output plain text, tex source, and pdf files. Independent of specific software frameworks, the program is applicable to many experiments. At present, it has come into use in three e + e − colliding experiments: the BESIII, Belle, and Belle II experiments. The use of the program in other similar experiments is also prospective. Program summary Program title: TopoAna CPC Library link to program files: http://dx.doi.org/10.17632/hjg4d9c843.1 Licensing provisions: MIT Programming language: C++ Nature of problem: A clear knowledge of the physics processes involved in inclusive Monte-Carlo samples is a great help to investigating signals and backgrounds in many high energy physics experiments. However, the raw topology truth information of the samples is counter-intuitive, diverse, and overwhelming, which makes it difficult for analysts to check the physics process information of the samples directly. Solution method: Based on accurate pattern matching, many kinds of fine, customizable classification and matching algorithms are implemented in this program, in order to help analysts obtain the physics process information of the samples from their raw truth information. Unusual features: Besides the C++ Standard Template Library, this program makes use of ROOT [1], a C++ based data analysis software universally used in modern high energy physics experiments. In addition, the program employs the Linux command, pdflatex, to compile the tex source files into the pdf documents. References [1] ROOT User’s Guide, Available online: https://root.cern/root/htmldoc/guides/users-guide/ROOTUsersGuide.html .