I've an app that is built in Xcode 4.2 (developer preview) and iOS 5, with deployment target iOS 4.0. I'm not using any of the iOS 5.0 features. Can I submit this build to Apple? Or is this a problem because it's beta? Should I go back to Xcode 4.02 and build it on 4.3?
You should absolutely never install beta builds SDKs as your primary SDK and version of XCode. Always keep the current install under /Developer (or wherever you choose) and install the beta in some other location (/iOS5Beta as an example). With this, when the new beta versions of XCode and the SDK arrive, you can uninstall the /iOS5Beta version and install the new one (may not have to uninstall, but just a point).
This allows you to beta test, then under the /Developer install do your regular development.
When the GM is out, you install that under /Developer and go.
You never submit Apps to Apple with beta builds of XCode and the SDKs.
Every readme file I remember for beta versions of Xcode have said they can't be used for submission. You have to use a GA version of Xcode to submit apps.
来源：https://stackoverflow.com/questions/6332511/iphone-submit-app-with-ios-5-and-xcode-4-2