电影讲述了20世纪初上海滩十里洋场、黑帮势力的角逐纷争。纷杂乱世中，奇女子筱月桂（余男 饰）与三代上海王之间充满传奇色彩的爱恨情仇。 　　在妓院做丫头的乡下女孩小月桂（李梦 饰），“个高、胸大、没裹脚”，让老板新黛玉（白灵 饰）很不满意，却深得洪门老大常力雄（胡军 饰）欢心，成为一代上海王的女人。常力雄在与同盟会代表黄佩玉（秦昊 饰）接触过程中被暗杀，小月桂孤助无援，产女后流落乡下。 　　历经数年艰辛，小月桂成立滩簧班子，重返大上海，在第二代上海王黄佩玉帮助下，成为“申曲名伶”筱月桂（余男 饰）。功成名就的筱月桂从没忘记要寻找杀死常力雄，也就是她女儿父亲的凶手。当她发现自己爱上黄佩玉时，也证实了“洪门内奸的真正身份”。她与常爷的前跟班余其扬（凤小岳 饰）合谋除去内奸，助余其扬成为洪门第一个银行家，新的“上海王”。The story is set in early 20th century. Country girl Cassia is sold as a maid to a Shanghai brothel, where Madam Shin considers her a no- count big foot with big breasts. But Cassia soon becomes the favorite of the triad Lord of Hong Men, Chang Lixiong - the Lord of Shanghai. Leaving a meeting with Huang Peiyu, Leader of Chinese Revolutionary League, Lord Chang is killed and Cassia is left alone and helpless. She is expelled to the countryside, where she gives birth to a daughter. After years of hardship, Cassia returns to Shanghai to scrape by with work in a local opera troupe. Under the patronage of the second generation triad Lord, Huang Peiyu, she rises to stardom in the Shanghai Opera. But when she discovers that Huang was implicated in Lord Chang's assassination, she persuades Yu Qiyang - who had served as attendant to both lords - to plot the murder of Huang and succeed him.