The Wildlife Conservation Society and staff from Russia's Sikhote-Alin Reserve teamed up for the mission.
The cubs have become the youngest wild tigers to be tracked by scientists.
They are concerned because about 50% of wild tiger cubs die in their first year. The collars will help them find out more about the cubs' needs.
The elasticated collars would fit on to a normal pet cat. They are designed to break and fall off when the creatures outgrow them.
Den
The cubs are the third generation of tigers to be tracked in the Russian Far East.
Their mum has a collar. The scientists waited until her signal showed she was away from her den before going in to fit the cubs with their collars.
Hear story 
Play Poacher Patrol!
Try the tiger quiz
'Tiger hunting is sickening'
