To spread the knowledge in the every sphere of the society the importance of a library is unlimited. In modern era library is the measuring element of the civilization. The usage of library proves that, which country or nation is the top of the education and culture. Indian sub-continent was very forward in this manner in the past. Aggamahapundit Professor Ven. Dhamma Bangsha Mahathero was the Abbot of Chittagong Buddhist Monastery, Pali teacher of Chittagong Collegiate School and the Professor of Pali of Chittagong Govt. College. The Chintamoni library has named after Dharma Bangsha Mahathero’s mother Chintamoni Barua in 1910. At first the library was placed in the 1st floor of the monastery. But for the water leakage of the roof it replaced in the hall of the same floor. The library again replaced in the room of the second abbot Ven. Dipankar Srigyan. This library has about six thousand (6,000) religious books of which the printed book of Burmese alphabet, Sri Lankan alphabet, Thai alphabet, Nagarik alphabet, act-words in Burmese, Sri Lankan & Thai alphabet, Pali dictionary, Bengali dictionary, English dictionary, Manual of Buddhism and also have The Gita, The Bible, The Quran etc.. The scarce traditional resources, like- tal-patra (palm-leaves), banana-leaves and wood-board written Puthi (manuscript) and Karmabacha has enriched the library. Researching inside of this library, Abdul Mabud Khan (1966) has gained his PhD. degree and Professor Dr. Hans Bechard of University of Gotengen of Germany has gained his Doctorate degree in 1969. In 1939 after the death of Aggamahapundit Ven. Dhamma Bangsha Mahathero, his worthy pupil Ven. Dipankar Srigyan Mahathero B.A. (Honours) has taken the responsibility of the library. Ven. Dipankar Srigyan Mahathro saved the sacred Hair relic of Buddha; 1kg gold made Buddha statue which are preserved in the monastery and Chintamoni Library which contains precious resources. He has made a microfilm of some scarce manuscript on the invitation of the University of Dhaka. Professor Ven. Shilachar Shastri Mahatero (M.A.) has taken the responsibility of the library after passing away of Ven. Dipankar Srigyan Mahathero.