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

Here is Why You Need An Adapter

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

China

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

Type A

Type C

Type I

Croatia

In Croatia, outlets of type C and F are in use.

Type C

Type F