艾米蒂岛是一个旅游度假胜地，有大批的游客来这里游泳。然而，大白鲨的出现却改变了这一切。事故从一对情侣开始，他们下海游泳，女的不幸成为了第一个牺牲者，支离破碎的尸体令人惨不忍睹。当地官员却不愿意封场调查，他们怕影响旅游收入，于是请来了生物学家布朗（理查德•德莱福斯 Richard Dreyfuss　饰）。 　　布朗断定，这是一只非比寻常的巨大白鲨。他的提醒并没有引起当局的足够重视，紧接着又有人死于非命，事态才变得越发严重。当地一个熟练捕鱼手、警察和布朗一共三人，决心要捕杀大白鲨，凶险重重的搏斗开始了，谁才是最后的胜者？要获得这场战斗的胜利，又要付出怎样的代价？It's a hot summer on Amity Island, a small community whose main business is its beaches. When new Sheriff Martin Brody discovers the remains of a shark attack victim, his first inclination is to close the beaches to swimmers. This doesn't sit well with Mayor Larry Vaughn and several of the local businessmen. Brody backs down to his regret as that weekend a young boy is killed by the predator. The dead boy's mother puts out a bounty on the shark and Amity is soon swamped with amateur hunters and fisherman hoping to cash in on the reward. A local fisherman with much experience hunting sharks, Quint, offers to hunt down the creature for a hefty fee. Soon Quint, Brody and Matt Hooper from the Oceanographic Institute are at sea hunting the Great White shark. As Brody succinctly surmises after their first encounter with the creature, they're going to need a bigger boat.