It's a little more complex than just one direction:
* Characters are written from top to bottom: The strokes that make up a character are generally written from top to bottom.
* Strokes can be written from left to right or right to left: Within a character, some strokes are written left to right, while others are written right to left. This depends on the specific character and the stroke order.
* Characters are written in columns: Chinese text is written vertically, with columns going from top to bottom. You read from right to left, starting with the column on the right.
So, it's a combination of directions, and it takes a little practice to understand the flow of Chinese writing.