In order to carry out their missionary work in Dai Viet, the Jesuits as early as the beginning of the seventeenth century tried to create a writing style based on the Latin alphabet, so that the Vietnamese language could be expressed. From the early attempts to transcribe names and place names, to the publication of the first two books of the National script in 1651, the collective efforts of Western missionaries allowed for the establishment of our writing today. Đe thuc hien cong cuoc truyen đao cua ho tai Đai Viet, cac giao si Dong Ten ngay tu khoang đau the ky thu XVII đa co gang tao nen mot loi chu viet can cu tren mau tu La Tinh, nho đo co the dien ta ngon ngu Viet. Tu nhung su do dam phien am cac nhan danh va đia danh luc ban đau, cho đen luc Đac Lo cho xuat ban hai sach Quoc ngu đau tien vao nam 1651, cac co gang tap the cua cac nha truyen đao Tay phuong cho phep thanh lap chu viet cua chung ta ngay nay.