The Taiwanese star, who won 12 titles worldwide last year and seven US LPGA Tour victories, will be hoping to repeat her 2011 win when the $1.5 million tournament tees off on Thursday at the Siam Country Club.
"I've been working hard and am looking forward to defending the title," she said Wednesday. "The course is in great condition."
Tseng endured the horrors of quadruple and triple bogeys in her last two rounds in this month's Women's Australian Open to finish joint eighth, two shots off the six-way victory playoff won by US teenager Jessica Korda.
Tseng has been working on a more powerful swing, which may have contributed to some of her wayward drives in Melbourne.
However, she said she was quite happy with her new swing.
"I'm not hitting it any longer, but I am more consistent," she said.
World number two Suzann Pettersen will be keen to pounce on any slip-ups.
The Norwegian has an impressive record in this event, never finishing lower than eighth. "I love this layout," she said at the par-72 course in the Thai resort city of Pattaya. "The greens are fast and true."
Michelle Wie performed well at last year's tournament when she finished runner-up to Tseng, and the big-hitting Hawaiian will be hoping to go one better this year.
Wie has her graduation coming up soon and a win in Thailand would be the icing on the cake.
"I've enjoyed the studying, but soon I will have more time to concentrate on golf," she said.
Showing good early season form has been America's Brittany Lincicome who came so close to winning last week's nail-biting six-player play-off in Australia.
Also in that play-off and performing in Thailand are South Korea's US Open champion Ryu So-Yeon and compatriot Seo Hee-Kyung, as well as Stacy Lewis of the US and Julieta Granada from Paraguay.
Among other leading golfers expected to be in contention this week are third-ranked Na Yeon-Choi, another Korean, along with the Americans Cristie Kerr and Paula Creamer, ranked fourth and fifth respectively.
Creamer has a big following in Thailand and will be among the favourites for the title.
"It's my first event of the season and I'm a little rusty," she said. "But the fans are really supportive here and I love it."
Japan's Ai Miyazato, ranked 11th in the world, won the tournament two years ago and after finishing well down the field last year will be looking to recapture her previous form.
There is also considerable interest in Thailand over the presence of teenage prodigy Alexis "Lexi" Thompson who has just turned 17.
Last year, at the age of 16, she became the youngest-ever player to win on the LPGA Tour with her triumph at the Navistar Classic.