A moderate quake measuring 5.3 on the Richter scale struck off western of Java island on Saturday, the Meteorology and Geophysics Agency reported here.
The quake jolted at 7:17 a.m. Jakarta time (0017 GMT) with the epicenter at 10 km deep, the agency said.
So far, no damage or casualty has been reported.
Indonesia lies on a vulnerable quake-prone zone called "the Pacific Ring of Fire."