Abstract: The sensitivity of Monilinia fructicola to boscalid was determined by the mycelial growth rate method. Meanwhile, the study investigated the biological characteristics of isolates with different sensitivities, the correlation between the amino acid mutations of SDHB protein with resistance to boscalid, and the cross-resistance of M. fructicola between boscalid and other 3 tested succinate dehydrogenase inhibitors (SDHIs), Y12196, penflufen and fluopyram. The results showed that boscalid had a good inhibitory activity and therapeutic effect against M. fructicola. However, M. fructicola has developed a certain degree of resistance, and the resistant isolates have comparable fitness with the sensitive ones. The sequence analysis of SDHB gene showed that the amino acid point mutations of M. fructicola SDHB subunits were not significantly correlated with the resistance to boscalid. The cross-resistance studies indicated that there was cross-resistance between boscalid and the other three SDHIs, Y12196, penflufen, and fluopyram. In order to retard the occurrence and exacerbation of resistance, the rational mixes or rotations of boscalid with other kinds of fungicides rather than SDHIs are recommended during the prevention and control of cherry brown rot disease.