Important things happen on Facebook. If you want to keep your memorable posts, Facebook has an export utility you can use to download just about everything related to your account. This includes posts, comments, photos, messages and even the ads you clicked on. Facebook doesn't have an option for exporting one specific post.
Log in to Facebook. Click the "Arrow" in the upper-right corner of any Facebook page and select "Settings" to open the General Account Settings page.
Click the "Download a Copy" link located at the bottom of the General Account Settings Page. This takes you to Facebook's Download Your Information page.
Click the "Start My Archive" button. Re-enter your Facebook password when prompted.
Click the next "Start My Archive" button that appears. Facebook sends you two emails. The first is a confirmation email, informing you that Facebook has received your request. The second email with the download link to your archive is sent within a few hours to several days later. If Facebook is unable to gather your archive, it sends you an email within three days asking you to try again.
If you don't want to wait for Facebook to compile your archive or if you want to save a post written by someone else, you can take a screenshot. On a Windows 8.1 computer, go to the post and press "Fn," "Space" and the "Windows" keys at the same time. The screen flashes, and the screenshot is saved to the Screenshots folder inside your Pictures folder.
Facebook also has an option for saving posts that contain videos and links that appear in your news feed. Just hover the cursor in the upper-right corner of a post in your news feed, click the "Arrow" and select "Save." Access saved posts at any time by clicking the "Saved" link in the left menu of your home page