This book is written to show the behavior, ecology and vectorial factors of tsetse flies mostly on the "Glossina Brevipalpis". These flies were caught so that they could be study more closely. Many method were used; odor baited epsilon, NGU2G, F3 and biconical traps. It has been noticed that the G. brevipalpis was easier to catch with electric screen. Species identification of trypanosome were then investigated for the latter. It was then concluded that the "G. brevipalpis"was a potential vector for the African trypanosomosis and hence, further studies on the ecology and control of this species are recommended