Victoria's critically endangered mountain pygmy-possums have a new, specially-designed "love tunnel" to help the furry creatures meet a mate.

The corridor has been built underneath the Great Alpine Road near Mount Hotham, which has previously been a barrier between male and female possums.

Typically, females live further up the mountain in a better quality habitat, with males living lower down the slope.

"We are making it easier and safer for the males to travel and breed with the females, by linking their habitats," state natural environment program officer Jerry Alexander said.

"We are giving this critically endangered species the best possible chance to thrive."

The mountain pygmy-possum is Australia's only hibernating marsupial, with only about 2000 left in the wild.

The species was thought to be extinct until one was discovered at Mt Hotham during the 1960s.