It's not quite that simple, A-shares are only for mainland investors but H-shares (listed on HK exchange) are available to trade by anyone. US based ADR's have

It's not quite that simple, A-shares are only for mainland investors but H-shares (listed on HK exchange) are available to trade by anyone. US based ADR's have received a lot of attention recently but they're not the only channel for foreign investment in China. BlackRock is also running a mutual fund of mainland equities.