Article in English: Enter your Google email and password and click “Sign in”. You will be taken the contacts profile of your account. You can also access this page by signing into Gmail and selecting “Contacts” from the “Gmail” menu in the top left corner. This option is listed in the left sidebar and will open a popup window to select a restoration period. If this option does not appear, click “More” in the left sidebar to expand the menu. The menu is expanded by default. You will need to choose a period before the changes to your contacts were made (e.g. if changes were made yesterday, you should choose a restoration period at least 2 days in the past). You can restore from a custom period if you do not want to use the default periods, but these are still limited to the 30 days in the past. This button is at the bottom of the restoration period window and will revert your contacts to the state they were in at the selected restoration period.

Summary in Chinese:
前往Google通讯录 单击“撤销更改”。 在列表中选择还原的时间点。 单击“恢复”。