Abstract： Objective:To analyze the genetic stability of two recombinant rotaviruses (rLLR/NSP3 NLuc) and (rLLR/NSP3 CoV2/RBD) that are inserted and express exogenous genes for continuous passage and proliferation on MA104 cells.Methods:After measuring the titers of two recombinant rotavirus strains, they were transferred to the P2 generation according to MOI0.01. Subsequently, the previous generation of virus lysate was diluted and activated at 1∶100, and MA104 cells were continuously infected for 18 generations (P20). The virus titers of the P1, P5, P10, P15, and P20 generation of cell lysate were measured using indirect immunofluorescence, and RT-PCR identification and dsRNA PAGE silver staining were performed. The luciferase activity of rLLR/NSP3-NLUc was also detected.Results:No inserted fragment loss was found in the recombinant rotavirus rLLR/NSP3 NLuc within 20 generations, with recombinant virus titers ranging from 3.85~5.16 × 10 6 FFU/ml, with strong luciferase signals in each generation. The recombinant rotavirus rLLR/NSP3 CoV2/RBD showed loss of inserted fragments in the 6th generation, with infectivity titers ranging from 2.6 to 3.36 in the first 5 generations of the recombinant virus × 10 6 FFU/ml. Conclusions:The recombinant rotavirus with 582 bp NLuc inserted at the end of the NSP3 gene has good genetic stability, while the recombinant rotavirus with 885 bp RBD inserted at the end of the NSP3 gene was only stable in the first 5 generations, indicating that foreign genes can be inserted at the end of the NSP3 gene of the recombinant rotavirus, and the insert can express, but its stability requires more in-depth research.