The 2010 MotoGP title-winner has only driven for the works Yamaha team in MotoGP so far, stepping up to its second seat alongside Valentino Rossi in 2008 after winning two 250cc championships.
Although Yamaha was beaten by Honda last year after three successive titles, Lorenzo said the team's general form over the past four years suggested he would be unlikely to look elsewhere when his contract expires at the end of 2012.
"When I first came to Yamaha in 2008 I already felt like I was in a family," said Lorenzo. "The ambiance is excellent. We had the perfect bike from 2008 to 2010. Last year was a difficult year. We didn't have a very competitive bike. But in general we always have a very good package.
"So my first option is Yamaha. I would like to finish my career at Yamaha. If the bike is competitive this year, I don't see any big motivation to change brand."
Lorenzo said Yamaha had made great strides over the winter, but still had to improve its electronics.
"We are in a process of evolution, trying so many things in every practice session - on the electronics, on the engine, on the chassis. We are throwing away the things that are not better and choosing the ones that are clearly better," he said.
"We are coming to the conclusion that we need to improve the electronics. On acceleration we are still not perfect - the bike moves a little bit. If I could choose one thing to improve, I would say the electronic system.
"We still have very good corner entry and the corner speed is very fast. We also improved top speed at the end of the straight. The acceleration and the electronics is the main point we must focus on."