How to import it from other project? Is the way to copy and paste the *.prefab file(s) to the other project folder? My prefab has some models,js,camera objects.I attempt to do it and gained a blank prefab.
Open up the project that contains the prefab and right-click on your project assets. Select “Export Package” and select the things you want to export (in this case, your prefab). Save it somewhere, then use “Import Package” in your other project.
Thanks for your reply. I test export package file to the desktop and when I use “Assets/Import package” import the file occur an error.See the screen shot follow. But if I copy and paste the package file to my project asset folder, I can find the file in the unity project view, Then double click the icon it can be decompress successful.
try to copy models and materials files to, which is used by prefab 
I was getting this error because the shared folder I was importing the shared assets from didn’t have full read/write access. Fixing that alleviated the problem.