ObjectiveTo systematically investigate the registration status, methodology and reporting quality of the systematic review protocols for animal experiment registered on PROSPERO platform.MethodsSystematic review protocols of animal experiments registered on PROSPERO platform were searched up to December 31st, 2019. Two reviewers independently screened literature, extracted data, and performed a descriptive analysis of the methodological quality and reporting characteristics of the included studies.ResultsA total of 351 protocols from 50 countries were included, involving 22 diseases. The intervention measures were primarily "pharmaceutical chemicals". Only approximately 1/3 of the studies reported the search strategy from at least one database, approximately half of the studies were prepared to report heterogeneity analysis and publication bias, and only approximately 1/3 of the studies were prepared to report sensitivity analysis.ConclusionsThe quantity of systematic reviews of animal experiments registered on the PROSPERO platform is increasing annually, however, there are still some limitations in the methodology and reporting quality.