The Fox Spirit of the Waste Land won the 14th BIB (Biennial of Illustrations Bratislava) Golden Apple Award in 1993, one of the first indigenous picture books from mainland China to receive international acclaim.

The story is an adaptation of The Merchant's Son, a classical Chinese fiction from Strange Tales from a Chinese Studio (Liaozhai zhiyi) written by Pu Songling (1640-1715 AD). In a patriarchal society like China, the son is the backbone of the family. So, in Cai's adapted version, Bao'er, a ten-year-old boy, has to shoulder the responsibility of looking after his mother while his father is doing business outside the town.

The little boy finds out his mother is being bothered (in the original tale the harassment is considerably more cruel) by a fox spirit and is determined to root it out, although Bao'er is a bit scared of what happened in the first place. The little hero then comes up with an idea to pretend to be a fox spirit and gives the offending spirit a bottle of poisonous wine. The fox spirit dies and Bao'er mother goes back to normal.

Chinese regard black as something mysterious and untouched, so Cai boldly uses black as the background color, fitting with the classical Chinese fiction's style. The delicate drawing of Bao'er's eyes has also helped Cai achieve international success.

The color of Bao'er's eyes changes from blue to black from time to time. Cai says she thinks kids are smarter than adults, and have clearer eyes. "When Bao'er's irises are as blue as a lake, everything (like the fox spirit) appears in its original, true shape," Cai said.