Ha Son Binh province had a geographical location: Ha Son Binh province had 24 affiliated district-level administrative units, including 3 towns: Ha Dong (provincial capital), Son Tay, Hoa Binh and 21 districts: Ba Vi, Chuong My, Da Bac, Dan Phuong, Hoai Duc, Kim Boi, Ky Son, Lac Son, Lac Thuy, Luong Son, Mai Chau, My Duc, Phu Xuyen, Phuc Tho, Quoc Oai, Tan Lac, Thach That, Thanh Oai, Thuong Tin, Ung Hoa, Yen Thuy.
On December 29, 1978, the two towns of Ha Dong, Son Tay and 5 districts of Dan Phuong, Hoai Duc, Ba Vi, Phuc Tho, Thach That and some communes of the district Quoc Oai, Thach That, Thanh Oai, Thuong Tin were admitted to Hanoi by resolution of the 4th session of the 6th National Assembly.
The province has 2 towns: Ha Dong, Hoa Binh and 16 districts: Chuong My, Da Bac, Kim Boi, Ky Son, Lac Son, Lac Thuy, Luong Son, Mai Chau, My Duc, Phu Xuyen, Quoc Oai, Tan Lac, Thanh Oai, Thuong Tin, Ung Hoa, Yen Thuy, with area of 5,978 km2, population of 1,569,000 people (1981).
At the same time, return Son Tay town and 5 districts: Dan Phuong, Hoai Duc, Ba Vi, Phuc Tho, Thach That of Hanoi city to Ha Tay province.
From August 1 year 2008, the entire area and population of province Ha Tay was merged into Hanoi City.