Where can I find a bigger bookstore in Xiamen?

It depends on what books you want.

There are books in general, Xinhua /Exograph/ Photosynthesis.

If it is a student's book, none of the above books can be found. I suggest you visit Hong Jie ~

Hong Jie has branches in Beth (outside the terminal of 52/53/54 Road) and Huli (Huli Chinese Business Logistics Station).