富绅董怀古生有一子四女：长子孟达，长女宝珠，次女静珠，三女丽珠，四女雪珠。二十年后董家已外强中干。孟达成为一个无赖；宝珠嫁一小官，自己成日赌博；静珠嫁了商人，生子体弱，便终日念佛，对善事却一毛不拔；丽珠嫁了小职员，爱慕虚荣，其夫苦不堪言；雪珠则与姑母办托儿所，为社会服务。怀古六十大寿，因董家曾向富豪杜家借款，孟达便对富豪之子杜豪百般巴结，甚至想法让其轻薄雪珠，幸亏雪珠机警小惩杜豪，寿宴不欢而散……

This is one of seven major propaganda films made by the Department Of Defense during World War II, and it's directed by Frank Capra.In this installment of the "Why We Fight" propaganda series, we learn about the country of China and its people. With a brief history of the country, we also learn of why the Japanese wanted to conquer it and felt confident about succeeding. Finally, the history of the war in that theatre is illustrated and shows the stiff determination of the Chinese who use all their resources to oppose Japanese aggression to the end.

抗日战争时期，有一支由三教九流人员组成的杂牌部队，号称新编第三团，团长为原县长段仁义（雷恪生 饰）。为调教这群乌合之众，国民党方面派来两个职业军人，参谋长方向公（袁苑 饰）和谭参谋（谭增卫 饰），并配备报务员白洁芬（宫主 饰）随队与上级联系。由于部队人员组成乌七八糟，各种违纪现象层出不穷，经肃纪整治稍有起色。大敌当前，国军主力撤退，命令新三团留守抵抗，后果可想而知。敌强我弱，方向公急电上峰求援，上峰找借口不予理会，新三团只好孤军奋战，伤亡惨重。段仁义安排上面派来的三人撤走，不料途中遭督战队截杀，仅白洁芬只身逃回。段仁义宣布解散部队，让大家各自逃生，却遭同党伐异......

周星星（周星驰 饰）是飞虎队队长，奉命以卧底的身份到圣育强中学寻找警司于参观时被窃的配枪。周星星就算百般无奈还是接受了任务。他很快适应了学校的生活，功夫高强的他也受到了学校众多学生的拥戴，周星星也顺势调查失枪案件。警队的另一位卧底曹达华（吴孟达 饰）也参与了这个案件，最后也与同学一起合力，帮助周星星破获一踪大型军火贩卖案件。