Can a USB 3.0 pen drive be used on a USB 2.0 port?

I want to buy a USB 3.0 pen drive. But in my pc there is only a USB 2.0 port.

Would a USB 3.0 pen drive work on my pc?

Yes, the various types and technologies of USB ports are generally designed to be backwards-compatible. However, there is no guarantee that this will be true in all cases.

You can find more information on Wikipedia.

USB 3.0 receptacles are electrically compatible with USB Standard 2.0 device plugs if they physically match. Most combinations will work, but there are a few physical incompatibilities.However, only USB 3.0 Standard-A receptacles can accept USB 3.0 Standard-A device plugs.