Yes you can. The following text is from the Safari help:
You can export your bookmarks from Firefox and use them in Safari.
To export bookmarks from Firefox:
- Open Firefox and choose Bookmarks > Organize Bookmarks.
- In the Firefox Bookmarks Manager, choose File > Export.
- Choose a location and name for the file. The default name is "bookmarks," and the default location is the My Documents folder.
- Click Save.
To import your Firefox bookmarks into Safari:
- Open Safari and choose File > Import Bookmarks. (If the File menu isn't visible, press the Alt key to show the menu bar.)
- Select the bookmarks file you created and click Import.
If these instructions don't work with your version of Firefox, check Firefox Help for instructions on exporting bookmarks.