The differences between China Unicom's Hong Kong stocks and China Unicom's A shares are: different listings, different transactions and different nature.

First, the listing methods are different.

1. China Unicom Hong Kong stocks: China Unicom Hong Kong stocks are listed on the People's Republic of China (PRC) Stock Exchange and the China Special Administrative Region.

2. China Unicom A shares: China Unicom A shares are listed on the China Stock Exchange.

Second, the transaction is different.

1. China Unicom Hong Kong stocks: You need to open an account in the Hong Kong market before trading China Unicom Hong Kong stocks, otherwise you can't buy them.

2. China Unicom A shares: To trade China Unicom A shares, you need to open an account in China market first, otherwise you can't buy them.

Third, the nature is different.

1. China Unicom Hong Kong stocks: China Unicom Hong Kong stocks are special RMB stocks.

2. China Unicom A shares: China Unicom A shares belong to RMB common stock.