You Do Need power plug adapter while traveling from Brazil to China.

Here is Why You Need An Adapter

The outlet and plug type used in China are A, C and I and in Brazil are C and N. This is how they look like.

Brazil

In Brazil, outlets of type C and N are in use.

Type C

Type N

China

In China, outlets of type A, C and I are in use.

Type A

Type C

Type I