Kanye West is reportedly not enjoying girlfriend Kim Kardashian's "full-on" personality.

The couple went public with their romance in April after several years of friendship.

Kim, who is still legally married to estranged husband Kris Humphries after filing for divorce 72 days following their wedding, is said to be scaring Kanye with her assertiveness.

The rapper believes that Kim's character traits mirror that of her momager mother Kris Jenner.

"Kris can be fearsome at the best of times, and Kim already shares some of her traits," a friend of Kanye's told the US edition of OK! magazine.

"Kim can be bossy, and she likes to be in control, getting her own way just like her mom.

"When they started dating, Kanye adored the way that Kim was assertive and ambitious. But now the novelty is wearing off. She's full-on all the time, and he can't ever relax."

It was rumoured that the pair were discussing marriage, but it is now believed that Kanye isn't too keen on the idea.

"Much as Kanye loves Kim, he's terrified that as she gets older she'll become more like her mom and he's not sure he can live with that," the source said.