希达、希伦、希棣和希素等四姊妹自小丧母，性格各有不同。希达贤良淑德，为了照顾父亲和三名妹妹，身兼母职，连自己的终身大事也置诸脑后；希伦风情万种，男人见一个俘虏一个，整日沉醉在被追求的甜蜜中；希棣爽朗好动，活像个小男生；希？？则娇俏柔弱，没丁点儿主见。在希棣的穿针引线下、大姐终觅得如意郎君，但一个转身，却被希伦勾引过去；希素也掉进了爱河，而且还决定与男友私奔，把急性子希棣弄得头昏转向！《四千金》的格局有点类似Loiusa May Alcott的经典闺秀小说《小妇人》，但郑慧的原著和陶秦的改编，却成功地给故事附予了一份强烈的时代感，四个女主角的性格也刻划得活灵活现，加上选角恰到好处（穆虹的大方得体、叶枫的千娇百媚、林翠的活泼生鬼、苏凤的小鸟依人），遂造就出一套百看不厌的时代经典。它的广受欢迎使陶秦在五九年拍了续集《兰闺风云》。

The Kong family has four daughters. Hilda, the eldest sister, assumes the role of a mother and often lets romance slip by. Third sister Hedy introduces her to Sun Ruhao, an engineer, but Sun is snatched by second sister Helen. The youngest girl Hazel drops out of school in pursuit of love. Hedy shows no interest in romance but is chased by a rich heir, He Yan. Meanwhile, Hilda runs away to meet her true love in a foreign land. As for Hedy, she is at last won over by He.