# 从老版本升级 请根据你要升级的版本阅读相应的升级注意事项。 [从 3.1.4 升级到 3.1.5](https://codeigniter.org.cn/user_guide/installation/upgrade_315.html) [从 3.1.3 升级到 3.1.4](https://codeigniter.org.cn/user_guide/installation/upgrade_314.html) [从 3.1.2 升级到 3.1.3](https://codeigniter.org.cn/user_guide/installation/upgrade_313.html) [从 3.1.1 升级到 3.1.2](https://codeigniter.org.cn/user_guide/installation/upgrade_312.html) [从 3.1.0 升级到 3.1.1](https://codeigniter.org.cn/user_guide/installation/upgrade_311.html) [从 3.0.6 升级到 3.1.0](https://codeigniter.org.cn/user_guide/installation/upgrade_310.html) [从 3.0.5 升级到 3.0.6](https://codeigniter.org.cn/user_guide/installation/upgrade_306.html) [从 3.0.4 升级到 3.0.5](https://codeigniter.org.cn/user_guide/installation/upgrade_305.html) [从 3.0.3 升级到 3.0.4](https://codeigniter.org.cn/user_guide/installation/upgrade_304.html) [从 3.0.2 升级到 3.0.3](https://codeigniter.org.cn/user_guide/installation/upgrade_303.html) [从 3.0.1 升级到 3.0.2](https://codeigniter.org.cn/user_guide/installation/upgrade_302.html) [从 3.0.0 升级到 3.0.1](https://codeigniter.org.cn/user_guide/installation/upgrade_301.html) [从 2.2.x 升级到 3.0.x](https://codeigniter.org.cn/user_guide/installation/upgrade_300.html) [从 2.2.2 升级到 2.2.3](https://codeigniter.org.cn/user_guide/installation/upgrade_223.html) [从 2.2.1 升级到 2.2.2](https://codeigniter.org.cn/user_guide/installation/upgrade_222.html) [从 2.2.0 升级到 2.2.1](https://codeigniter.org.cn/user_guide/installation/upgrade_221.html) [从 2.1.4 升级到 2.2.x](https://codeigniter.org.cn/user_guide/installation/upgrade_220.html) [从 2.1.3 升级到 2.1.4](https://codeigniter.org.cn/user_guide/installation/upgrade_214.html) [从 2.1.2 升级到 2.1.3](https://codeigniter.org.cn/user_guide/installation/upgrade_213.html) [从 2.1.1 升级到 2.1.2](https://codeigniter.org.cn/user_guide/installation/upgrade_212.html) [从 2.1.0 升级到 2.1.1](https://codeigniter.org.cn/user_guide/installation/upgrade_211.html) [从 2.0.3 升级到 2.1.0](https://codeigniter.org.cn/user_guide/installation/upgrade_210.html) [从 2.0.2 升级到 2.0.3](https://codeigniter.org.cn/user_guide/installation/upgrade_203.html) [从 2.0.1 升级到 2.0.2](https://codeigniter.org.cn/user_guide/installation/upgrade_202.html) [从 2.0 升级到 2.0.1](https://codeigniter.org.cn/user_guide/installation/upgrade_201.html) [从 1.7.2 升级到 2.0](https://codeigniter.org.cn/user_guide/installation/upgrade_200.html) [从 1.7.1 升级到 1.7.2](https://codeigniter.org.cn/user_guide/installation/upgrade_172.html) [从 1.7.0 升级到 1.7.1](https://codeigniter.org.cn/user_guide/installation/upgrade_171.html) [从 1.6.3 升级到 1.7.0](https://codeigniter.org.cn/user_guide/installation/upgrade_170.html) [从 1.6.2 升级到 1.6.3](https://codeigniter.org.cn/user_guide/installation/upgrade_163.html) [从 1.6.1 升级到 1.6.2](https://codeigniter.org.cn/user_guide/installation/upgrade_162.html) [从 1.6.0 升级到 1.6.1](https://codeigniter.org.cn/user_guide/installation/upgrade_161.html) [从 1.5.4 升级到 1.6.0](https://codeigniter.org.cn/user_guide/installation/upgrade_160.html) [从 1.5.3 升级到 1.5.4](https://codeigniter.org.cn/user_guide/installation/upgrade_154.html) [从 1.5.2 升级到 1.5.3](https://codeigniter.org.cn/user_guide/installation/upgrade_153.html) [从 1.5.0 or 1.5.1 升级到 1.5.2](https://codeigniter.org.cn/user_guide/installation/upgrade_152.html) [从 1.4.1 升级到 1.5.0](https://codeigniter.org.cn/user_guide/installation/upgrade_150.html) [从 1.4.0 升级到 1.4.1](https://codeigniter.org.cn/user_guide/installation/upgrade_141.html) [从 1.3.3 升级到 1.4.0](https://codeigniter.org.cn/user_guide/installation/upgrade_140.html) [从 1.3.2 升级到 1.3.3](https://codeigniter.org.cn/user_guide/installation/upgrade_133.html) [从 1.3.1 升级到 1.3.2](https://codeigniter.org.cn/user_guide/installation/upgrade_132.html) [从 1.3 升级到 1.3.1](https://codeigniter.org.cn/user_guide/installation/upgrade_131.html) [从 1.2 升级到 1.3](https://codeigniter.org.cn/user_guide/installation/upgrade_0.html) [从 1.1 升级到 1.2](https://codeigniter.org.cn/user_guide/installation/upgrade_120.html) [从 Beta 1.0 升级到 Beta 1.1](https://codeigniter.org.cn/user_guide/installation/upgrade_b11.html)