Compared to the attention given fertility changes in the developing world recent mortality trends have received little notice.Yet there are indications that developing world mortality patterns are also evolving in ways that are potentially important for for the human welfare that constitutes the principle basis for constitutes the principle basis for concern with population issues.in particular the suggestion emerging from recent finding is that the remarkably rapid rates of mortality decline that have prevailed since world war 11 have begun to falter, to give way to a confused, diverse, ambiguous situation marked by unexpected slow downs in the pace of health improvements observed in many large areas of the developing world.