The rhythmic bursting of excitatory neurons in the pre-Botzinger complex is closely related to the respiratory rhythm generation.Leakage current plays an important role in regulating the bursting pattern of neurons.We studied the influences of the leakage current on bursting synchronization and transition mechanisms by both two-parameter bifurcation analysis and fast/slow decomposition.The results show that, under different initial conditions, the coupled cells can exhibit “fold/homoclinic” type and “subHopf/homoclinic” type bursting for inphase synchronization, and exhibit “fold/fold cycle” type and “subHopf/fold cycle” type bursting for antiphase synchronization.This work provides insights into the study of the respiratory rhythm.