Ho Si Phan was born in 1921 in the district of Vinh Loc in Thanh Hoa. He was the director of the bank of Thanh Hoa from 1946 to 1948, then a member of the Thanh Hoa Administrative resistance committee (Uy ban khang chien hanh chinh) from 1948 to 1953, and finally head of the financial department (Ty Tai chinh tinh) of Thanh Hoa from 1951 to 1953.