after finishing my android application development i used the command showing below to get private key, but it shows some errors such as “The Keystore was tampered with or password was in correct”
$ keytool -genkey -v -keystore DEBUG.keystore
-alias alias_name -keyalg RSA -keysize 2048 -validity 10000
Is my problem with DEBUG.keystore?? Should i need to generate another keystore for public release??
Yes, you should definitely generate another key for public release (and keep it in a save place for future updates).
See http://developer.android.com/guide/publishing/app-signing.html#releasemode for details.
EDIT:
If you’r using Eclipse, use the ADT Plugin for Android to create your keyfiles and sign your application.