Abtract: Hearing screening for children in pre-school in Hai Duong and Thanh Hoa provines. Method in cross - sectional survey 9,687 children in public preschool. Results: 1,882 children in Thanh Hoa and 7,805 children in Hai Duong provice. 52 percent boys and 48 percent'girls. 2.1 percent children with hearing loss. Otitis Media is main reson cause hearing loss in this group 92/204, History of meningitis 11/204... All most children with hearing loss have threshold under 40dB. Conclusions. This study informs public health. The author know that, the rare of hearing loss in pre-school are very high, there are many resons can cause hearing loss in children. It is better to continous for studying this topic.