In Android Programming using Eclipse IDE, you can load a pre existing project into your workspace. This can be attain by the following five steps.
Open eclipse (of course).
Click "File" in the menu bar then New->Project
Select "Android Project from Existing Code" in the pop up window.
Click "Browse" and locate the folder of the Android Project.
Click the checkbox under "Project to Import" and the checkbox beside "Copy project into to workspace" then click "finish".
There you go, your Android Project is now on your workspace and ready to be run or edited.