Sample size was selected randomly systematic. Results: Risk factors associated with preterm in Binh Phuoc consist of: age of mother under 20 OR=3.3 CI95% (1.20 - 10.80), history of preterm birth OR=3.16 CI95% (1.13 - 10.16), farmer OR=3.48 CI95% (1.92 - 6.34), night working in pregnant time OR=3.81 CI95% (1.63 - 9.66).