Police will be targeting excessive drinking and underage gambling during the Melbourne Cup carnival.

Victoria Police Assistant Commissioner Andrew Crisp said a major police operation would be targeting anti-social behaviour in and around the Flemington racecourse.

He said people should enjoy the carnival responsibly.

"We're not wowsers. We're not the fun police," Mr Crisp said, as he urged racegoers to look out for their mates.

"A $704 on-the-spot fine makes it an expensive day."

The $700-plus penalty will be issued to people behaving in a drunk and disorderly manner.

Police ejected more than 150 people from Flemington racetrack on Melbourne Cup day last year.

But the Victoria Racing Club said crowd behaviour has been improving.

VRC executive general manager for Flemington Mark Davies said there had been an 84 per cent decrease in incidents at the carnival over the past five years.

Uniformed and plain clothes police will be targeting excessive drinking, and underage gambling and drinking, while officers will also focus on anti-social behaviour in general and drink-driving.