My issue is quite different from other posts on stackoverflow, such as How to migrate a codebase from one svn repo to another preserving history?.
It is easy to migrate an svn repo from one pc to the other, since I have full control of these pcs. What should I do if I want to migrate a local svn repo to google code's svn repo?
Seems svnadmin dump and load can only be used to local URI.
So is there any other method that I can use to import a local svn dump to google's svn host?
There's a tool called svnsync which should do what you want - it essentially reads every revision from the source repo, then plays them back to the destination repo.
Be careful if you're planning to mirror between two repos, as things can get a bit out of hand; however, for a one-off migration, svnsync is probably the most straightforward option.