Abstract: By using an f-plane barotropic quasigeopotential model in the rectangular coordinate with the grid space of 5 km,ten experiments whose integration times are 36 hours are performed in order to study the interaction between a mesoscale vortex and a typhoon vortex,the initial position of the center of the mesoscale vortex is located in northwest direction to the typhoon center,with the distance between two centers being 2 rm,where rm is the radius of maximum wind of the typhoon vortex.Results show that the interaction can crest a pair of smaller scale vortices or lumps,which extend from the outside region of the typhoon to near its center,resulting in the mesoscale vortcity propagation into the inside region.In this process,the vorticity concentration of the mesoscale vortex may appear.The coexistence of the propagation and the concentration makes the increase of vorticity in the inside region and more intensive typhoon.Meanwhile,the intensity of the lump with positive vorticity changes with time,with the oscillation period being several hours,the change of distance from the typhoon center to the lump center has a similar oscillation period,which reduces the oscillation of typhoon intensity.In the case of stronger circular basic current,the interaction can make the intensification of typhoon more obviously.In addition,in some parametric conditions,the interaction may break down the continuous vorticity zone,exhibiting a cluster of smaller vorticity lumps.