The meeting was attended by caretaker Deputy Defence Minister Yutthasak Sasiprapa, supreme commander Thanasak Patimapragorn, army chief Prayuth Chan-ocha, navy chief Narong Pipattanasai, and air force chief Prajin Jantong.
A source said Mr Yingluck had an informal talk with the military top brass for about one hour, during which they discussed the political situation and the imposition of the emergency decree, before the official meeting of the Defence Council.
According to the source, the prime minister asked the armed forces chiefs to be strict in controlling the distribution of weapons from arsenals, for fear they could be taken out without proper supervision to cause trouble.
They also discussed the role of the military under the Executive Decree for Administration in an Emergency Situation and cooperation with police in night operations.
The armed forces chiefs were also told to make sure soldiers under their supervision exercise their voting right on election day, Feb 2.
They were asked to make sure that their subordinates are careful in their use of the social media, through which distorted information and fabricated news have been disseminated.