Abstract: The ionosphere serves as a crucial link between the magnetosphere and the middle to upper atmosphere, and it is a key region for energy transfer and coupling in the Sun-Earth system. Advances in ionospheric research are therefore essential for understanding space weather impacts and for improving the resilience of communication and navigation systems. Partly, ionospheric irregularities such as equatorial plasma bubble (EPB) and medium scale traveling ionospheric disturbances (MSTIDs) have attracted sustained attention. EPB and MSTIDs are two representative classes of irregularity structures in the low and mid latitude ionosphere. Their morphology and evolution provide important diagnostics of ionospheric dynamics. This review summarizes recent progress on interaction processes involving EPB and MSTIDs, the relevant literature could be categorized into three types: EPB-EPB interactions, MSTIDs-MSTIDs interactions, and EPB-MSTIDs interactions. EPB-EPB interactions are primarily manifested as EPB merging, whereas MSTIDs- MSTIDs interactions typically involve head on propagation and overtaking scenarios. EPB-MSTIDs interactions, by contrast, usually result in the dissipation of either structure. Across these interaction scenarios, changes in the ionospheric background parameter, for example neutral winds and ambient electric fields, play an important role, while polarization electric fields generated by the irregularities themselves may be pivotal in regulating the interaction outcomes. However, reports of such interaction events remain relatively sparse, leaving their occurrence characteristics and evolutionary pathways insufficiently constrained. Furthermore, existing physical interpretations are still largely tentative, highlighting the need for systematic cross validation through more observations and numerical simulations.