Kim Kardashian is "anxious" about saying her wedding vows.

The 30-year-old socialite - who is set to marry basketball star Kris Humphries on Saturday (20.08.11) - is nervous about what she has to say at the altar and has decided to write her own vows instead of using the traditional promise to her husband.

A source told America's OK! magazine: "The one thing that was making her anxious was her vows. She wanted them to be just right and wrote them herself. Kim also had a hard time deciding what song to use for their first dance."

Not only is Kim nervous about her walk down the aisle - her mother Kris Jenner is desperate to see all the "hard work" preparing for the event conclude in a "beautiful moment" with the vows.

She said: "The actual 'I dos' are the moment that all of our hard work and all of her love and everything culminates into - this one beautiful moment."

Kim - who is planning to wear a Vera Wang dress - has previously admitted to being scared of fainting with nerves on to her step-father Bruce Jenner when she walks down the aisle.

She said: "I was so nervous to walk down the aisle by myself.

"For some reason I wasn't thinking, like, 'Oh, Bruce will be there right with me,' so I was thinking, 'I'm gonna fall, I'm gonna faint, oh my God, my train!' "