"It's wonderful to be able reach out to my well-wishers and loved ones moments of one's life - sometimes through texts, videos, audio clips...Now it's time for a whole new graphic medium - Instagram, where I can tell my stories through pictures," Bachchan said in a statement issued by Instagram.
He added that the endeavour is to communicate and keep in touch with as many as possible in as many different ways and mediums.
"... be privy to some pictures of me, some by me! Aah, the camera, the lens, the filters, the colours, the effects... Let's spin some magic instantly!" he said.
The veteran actor is already into blog, Twitter and Facebook.
Instagram has more than 100 million registered users and over 32 million photos posted per day.
Celebrities including Madonna, Kim Kardashian, Rihanna, Justin Bieber, Priyanka Chopra are among users of this social networking application, the statement said.