All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.
If what you mean is to ask about the ruling on the fees taken for entering zoos and wildlife parks and the like, then the answer is as follows:
There is nothing wrong with visiting zoos in order to see the animals, enjoy their shapes, their different species and colors, and, get to know about their lifestyles and their nature, and this is a permissible benefit. So it is permissible to take a fee in return for it.
Rather, this may become an act of worship if the visitor intends to contemplate the creation of Allaah, reflect on His signs by watching those animals, and ponder as to how Allaah had created them. Allaah says (what means): {Then do they not look at the camels - how they are created?} [Quran 88:17] Allaah also says (what means): {Do they not look into the realm of the heavens and the earth and everything that Allaah has created.} [Quran 7:185]
The owners of these zoos and parks are not obliged to let people visit those animals free of charge; therefore, they are entitled to charge people fees for visiting those animals and looking at them.
Allaah knows best.