Although Regional integration in Africa has a long history which dates back to the and of 19thrncentury, it has failed to achieve its objectives, Several studies have pointed out different factorsrnwhich contribute for its poor performance. These factors include loss of revenue due to tradernliberalization non-complementarily of tradable goods, poor private sector participation,rnoverlapping of memberships and so on. his study assessed and analyzed the problems andrndeterminants Africa regional trade integration in general and COMESA in particular. however,rnit gives a due attention to determine the impact of trade openness ( trade liberalization) andrnoverlapping of memberships on top of other determinants ( GDP, precipitate GDp, commonrnboundaries, common language of member countries, distance between member countries etc.) onrnCOMESA total trade flow using gravity model approach.rnThe study comes up with the finding that trade openness (trade liberalization) within COMESArnmember countries boosts the intra-trade flow of the region. in contrast to this, overlapping ofrnmembership results in decline for the intra- trade flow of COMESA. Thus, the study recommendsrnthat COMESA member countries should liberalize their trade ,diversify the tradablerncommodities ,increase private sector participations and they should not to be a member of morernthan one regional group.