随着信息时代的到来，越来越需要一种有效的管理方法来组织日益庞大的信息量，X．500以其合理的数据组织结构和高效的数据处理方式成为建立企业级信息库的首选方案。可是复杂的ISO协议栈限制了X．500的应用范围；也阻碍了X．500的发展．LDAP的出现解决了这个问题，使用LDAP用户可以在不增加客户端负担的情况下实现访问X.500目录库的功能。LDAP的出现大大加速了目录系统的发展，而LDAP本身已经成为事实上的目录访问标准协议。 With the advent of the information age, there is an increasing need for an effective management approach to organize an ever-increasing amount of information, 500 with its reasonable data structure and efficient data processing methods to become the first choice to establish an enterprise-class information base. However, the complex ISO stack limits the X. 500 range of applications; also hindered the X. 500 development. The advent of LDAP addresses this issue, enabling LDAP users to access the X.500 catalog without increasing the client’s overhead. The advent of LDAP has greatly accelerated the development of directory systems, and LDAP itself has become the de facto directory access standard protocol.