公益广告(public service advertisement)指为社会公众的利益和社会风尚服务的广告。它不以盈利为目的，属于非商业性广告，是社会公益事业(cause of the public good)的重要组成部分。公益广告的主题一般取材于老百姓的日常生活，如健康、安全和环保等。目的是提高公众的道德意识，改变公众对社会问题的态度。中国最早的公益广告出现在1986年。随后，公益广告的社会影响力逐渐增强。去年,中央电视台举办了首次电视公益广告大赛，呼吁社会各界关注并参与公益事业。英语六级攻略

参考翻译:

Public service advertisement refers to the advertisement that serves the interests of the public;and social fashion. As a significant part of the cause of the public good, it is noncommercial and does notaim at making profit. The themes of public service advertisements generally come from the daily life of ordinary people, such as health, safety andenvironment protection.Its objectives are raising public awareness of ethics and changing public attitudes towards social issues. The earliest public service advertisement in China appeared in 1986. From then on, its social influence heightened gradually. Last year, CCTV hosted China’s first public service advertising competition, appealing to people in all walks oflife to concern about and participate in the cause of the public good.