The award is for his efforts to bring the library and books to the common man in Kerala.
The MaLA, founded by Dr S R Ranganathan on January 31, 1928, is celebrating its founder's 125th birth anniversary, a release said.
Ranganathan's student and colleague, 101-year-old S. Parthasarathy conferred the award.
In a career spanning 38 years, Subramoni worked in the British Library Thiruvananthapuram for 33 years and was the Chief Librarian from 1993 to 2008.
Ranganathan is remembered as the Father of Library Science in India and was the first librarian of the Madras University (1924).
Those present at the function included MaLA president Prof; Dr. K Nithyanandam, Director of Public Libraries Dr S Kannappan and former Anna University Vice Chancellor Prof:Dr. D. Viswanathan.