Jermaine Jackson -- Pay Child Support, Or Go Directly To Jail

Jermaine Jackson could be playing to 5,000 people soon ... the inmates at a L.A. County Jail ... a place he may be calling home soon if he doesn't ante up back child support.

Jermaine is falling farther and farther behind .... he's required to pay baby mama Alejandra Jackson $3K a month for 13-year-old Jermajesty and 17-year-old Jaafar … but the mailbox has been empty for months.

Court docs obtained by TMZ show … of the $12K that he owes in back payments … he’s only coughed up a measly 85 bucks.

The L.A. County Child Support Services Dept. has filed papers asking a judge to hold Jermaine in contempt ... which could put him behind bars for 20 days.

BTW, this isn’t the first time Jermaine has slacked off. He belatedly paid $80,000 back in March 2011 … and anted up another $33K in back support this past May. He's also had his wages garnished.