Hello , can you tell me if i can buy one ticket for buses and metro? Like oyster card in London.

Yes. There is Yangcheng Tong transportation card, which can be used on bus and metro. You need to top up the card in advance, and every time you use it, you just need to swipe it simply.

If you don’t buy the card, you need to buy the tickets on the bus. There will be staff on the us selling the tickets, or you need just insert the money to the money box. Most occasions, the tickets will not be validated, you just keep it well. Some bus charges 2 Yuan (CNY), some less or more than that.