本文介绍了一种使用单片机和555 集成电路制作电缆报警器的方法。通过555 集成电路和单片机配合，再加上校验功能，可以比较精确地测量出断缆距机房的距离，为电信运营提供了一种性价比较高的电缆防盗报警装置。〔关键词〕电缆防盗报警； 555 集成电路； 单片机〔Abstract〕This p aper introduces a method how to do a guard against theft and alarmsystem of cable ,using 555 integrate circuit and MCS-51 MCU.Through the cooperationof 555 integrate circuit and 51 MCU and the verification,it can measure the distanceof the cable which were cut accurately.It provides a cheap and high performanceequipment for telecommunication corporation.〔key word〕cable annunciator;555 integrate circuit;MCU