"She's not testing the waters. She's charting the course. She's in with both feet," a close associate of Harris was quoted as saying by The Los Angeles Times.
The current Senator Barbara Boxer, 74, has announced that she would not run for re-election in the 2016 elections.
A close confidant of the US President Barack Obama, Harris is considered to be a rising star in the Democratic Party.
If elected Harris, 50, would be the first ever Indian- American elected to the US Senate.
So far, only three Indian-Americans have been elected to the US House of Representatives: Dalip Singh Saund, Bobby Jindal and Ami Bera, who was re-elected for his second term last November.
It is only last week that Harris was sworn in for her second term as the California Attorney General.
