The　synthesis　of　cyclic　polymer　is　an　important　topic　in　polymer　chemistry.　Herein,　we　report　a　one-step　method　to　prepare　cyclic　polypyrazoles.　Monomers　with　two　functional　groups,　diazo　and　alkyne,　were　synthesized　and　polymerized　via　1,3-diploar　cycloaddition　in　bulk　under　heating　without　any　catalyst.　Polypyrazoles　with　molecular　weights　in　the　range　of　3800-4400　g/mol　and　yields　in　the　range　of　78.8-98.7%　were　successfully　synthesized.　No　chain　end　group　was　detected　by　LC-QTOF-MS　and　FTIR,　which　proves　the　cyclic　structure　of　polypyrazoles.　What　is　noteworthy　is　that　the　cyclic　polypyrazoles　can　self-assemble　into　vesicles　during　the　reprecipitation　process,　which　was　proved　by　the　results　of　SEM　and　TEM.　The　reason　for　that　is　the　formation　of　intermolecular　hydrogen　bond　between　NH　and　ester　groups.　(C)　2021　Published　by　Elsevier　B.V.　on　behalf　of　Chinese　Chemical　Society　and　Institute　of　Materia　Medica,　Chinese　Academy　of　Medical　Sciences.