Abstract: [Objective]To further enhance ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) synthesis efficiency.[Methods] We cloned Halomonas salina DSM 5928T teaABC gene of ectoine-specific transporter TeaABC by walking PCR and constructed ectoine absorption defective mutant H. salina DSM 5928T (teaABC-) by Red recombination technology.[Results] The total concentration of ectoine and productivity in a 10 L fermentor were 9.10(±0.08)g/L and 9.93(±0.09)g/L.d.[Conclusion] The ectoine absorption defect mutant H. salina DSM 5928T(teaABC-) compromised the negative feedback regulation of ectoine synthesis,which can significantly improve the efficiency of ectoine production.