According to TMZ, the crooks seemingly got in through a window or door on an upper floor, as a ladder was found in the back yard, reorts news.com.au.
No one was home at the time of the robbery.
The 'Touch My Body' hit-maker is currently in New York.
Mariah has joined a long list of stars whose Los Angeles homes have been burgled, including Jason Derulo, Scott Disick, Kendall Jenner, Alanis Morissette, David Spade and Emmy Rossum.
Despite the high value, it is believed only around 10 items were stolen from Mariah, but it is unclear what they were.
As per reports, the case is under investigation. (ANI)