So many of them are being killed by people that conservationists think as many as two-thirds of the world's tortoises and freshwater turtles are at risk.
The scientists say that some species could even be extinct within 20 years.
The main reason the reptiles are dying out is because in many places in Asia they are used in medicine or even as expensive food.
The Turtle Conservation Fund say that tonnes of live turtles are taken into southern China every day, and that once some species are gone, they're gone for good.
The fund hopes that the money they raise will be able to help keep more species of turtles and tortoises alive with special breeding programmes and farming.