Barzagli admits he was convinced about the switch after talks with Juve coach Gigi del Neri.
"I spoke to Del Neri and he seemed very determined, maybe even more than in the past," he said.
"I have arrived at a great club, the biggest I have ever played for, and am here to give my contribution.
"I have watched Juventus, so I think that despite the changes and injuries, they are having a good season. They're only two to three points from the Champions League spots.
"This is a compact and unified squad with excellent potential. We can only improve with these resources at our disposal."
Barzagli added: "This season a new director of sport arrived at Wolfsburg with two new centre-backs, so I was pushed aside.
"I was meant to leave in August, but was then held because Arne Friedrich picked up an injury, so I agreed to stay on until he recovered.
"These were a positive two and a half years in Germany and a satisfying time too, considering we won the Bundesliga in the first season. It may seem strange that I was signed for 11m and sold for 300,000, but in Germany this happens a lot."