This paper investigates the effect of rheological behavior on dynamics of bubble coalescence. In situ observations on polymers with different rheological behaviors were conducted to study coalescence dynamics. Four patterns of interface deformation were observed. Deformation during coalescence was analyzed by applying image-processing schemes and rheological models to the in situ observations. Polymer with Newtonian behavior showed nucleation and coalescence of spherical bubbles that created a planar interface. The planar interface was deformed by a combination of biaxial and planar elongational flows. Coalescence in polymers with non-Newtonian behavior is characterized by penetration with a parabolic shaped interface. The deformation of parabolic interface was due to biaxial elongational flow. However, the interface deformation of the polymer with cross-linked structure was due to an integration of biaxial and elongational flow. Further, cross-linking was also observed to have an effect on coalescence time.