Melbourne- Serena Williams enters the Australian Open as a strong favourite to lift the Daphne Akhurst Memorial Cup but is all too aware that a sixth Melbourne Park title has now eluded her for five years.

"I've been going for number six for a number of years now," the world number one told reporters on Saturday.

"It would be really special for me. I would be really happy. I want it I think more than anyone else here.

"But that doesn't mean I'm going to get it, so I'll have to fight hard to get it."

The 33-year-old American won her last Australian Open in 2010 and while she missed the 2011 event due to injury, she has not advanced past the quarter-finals in the past three years.

She suffered a surprise fourth round loss to Ekaterina Makarvoa in 2012, lost a quarter-final to Sloane Stephens the next year and was bundled out by Ana Ivanovic in the fourth round 12 months ago.

Her preparations for this year's event have been less than ideal, suffering losses to both Eugenie Bouchard and Agnieszka Radwanska at the exhibition-style Hopman Cup tournament.

Even in her victories in Perth, she was not her dominant self and her frustrations boiled over as she smashed a racquet and had a running battle with a chair umpire in the final against Poland.

"I'm not very happy with it but I'm never really happy about my practice or preparation, so maybe that's a good sign," Williams added when asked about her form heading into the year's first grand slam.

"I definitely feel better now than I did a couple weeks ago. But I still want to improve some things. I feel like I should be doing some things better.

"But every day I can see something coming through, so... there's a little light at the end of the tunnel."

While the last few years had slow starts, Williams has made a habit of finishing strongly, none more so than last season when she went 22-2 after Wimbledon and won her sixth U.S. Open and fifth WTA Finals title.

The victory at Flushing Meadows brought her career grand slam tally to 18, tied with Chris Evert and Martina Navratilova as fourth best of all time.

Helen Wills Moody won 19 titles, while Germany's Steffi Graf won 22 and Australia's Margaret Court claimed 24 titles.

Williams acknowledged Graf's total was in her sights, though she also said winning another four grand slams was going to be a relatively difficult job.

"22 is so far away from 18. When you're 18 years old, you look at someone that's 21, you think they're old. So it's a really big distance to get to 22.

"I can't think that far ahead. I just have to think about 2015 at the Australian Open in particular."