<正>In the last two decades and particularly in the past several years,due to the unprecedented changes in the world’s media landscapes that have been caused by the drastic changes in political,economic,and cultural factors,public broadcasting across the globe has encountered many new and much tougher challenges and problems,especially the challenges from transnational,international and global commercial broadcasters.Various public broadcasting services have responded in various ways.Using a comparative analysis approach,this study examines the recent challenges and problems public service broadcasting has encountered,how the world’s leading public broadcasters have responded,and what the current situations of the leading public broadcast services are.Specifically,this research analyzes five major public broadcasters:the British Broadcasting Corporatinn(BBC),the Public Broadcasting Service(PBS) of the United States,the Canadian Broadcasting Corporation(CBC),the Nippon Hoso Kyokai (NHK)of Japan,and the Australian Broadcasting Corporation(ABC).The key issues discussed include the overall media environment of the respective countries,the various government policies on public broadcasting,the competition and surviving strategies of these public broadcasting services,and the relevant national and international political,economic and societal factors that have influenced or altered the respective media industries.A conclusion section attempts to draw the implications of this study’s findings.