Phillips missed the 2008 Games in Beijing after an injury to Toytown
Zara Phillips is looking at "two or three" horses in her attempt to win a medal at the London Olympics in 2012.
Phillips hopes to make up for the disappointment of missing Beijing in 2008 after her ride, Toytown, was injured two months before the start.
"Toytown was one of the best horses in the world but you cannot stop injuries from happening," said the 29-year-old.
"To have two or three horses without injuries that would do - to have those as a back-up plan."
Phillips, who did not reveal any names or pedigrees about potential new horses, added that it would be "amazing" to make her Olympic debut at the Games in her home country.
"I think that everyone went out when we heard that London got the Olympics and went looking trying to find something that would be the right age and experience for 2012," she continued.
"There have been a lot of people [potential Olympic medallists] who have been in the running and had to pull out because of having a horse injured, and hopefully I will get there."
Phillips won the individual title at the World Equestrian Games on Toytown in 2006 and individual and team gold at the European Eventing Championship on the same ride in 2005.
However, she has ruled out defending her world title with Toytown at Kentucky in October 2010.
"I have had my horse of a lifetime. I was very young and had fantastic results and the horses I have had since then have been in a massive shadow," added Phillips, who was named BBC Sports Personality of the Year in 2006.
Of the controversy surrounding the choice of Greenwich in south-east London as the stage for 2012 equestrian events, rather than a more traditional venue, she stated: "To be honest, I do not mind as long as I am there competing.
"I think that any athlete wants to be there rather than thinking about the rest of it."