According to population statistics of 1936, the then Kuomintang Republic of China had an estimated 48,104,240 Muslims. Below is a reference from about the Muslim population before Communist Revolution:
“There are in China 48,104,241 Mohammedan followers and 42,371 mosques, largely in Sinkiang, Chinghai, Manchuria, Kansu, Yunnan, Shensi, Hopei, and Honan. “Ferm, Vergilius (ed.). An Encyclopedia of Religion; Westport, CT: Greenwood Press (1976), pg. 145. [1st pub. in 1945 by Philosophical Library. 1976 reprint is unrevised.]
Under the pretext of unification of national education, Islamic schools were closed and their students transferred to other schools which taught only Marxism and Maoism. Other outrages included the closing of over 29,000 mosques, the widespread torture of imams, and executions of over 360,000 Muslims. Aside from the physical annihilation, Muslims have been subjected to a constant attack on their Islamic identity especially during the so-called Cultural Revolution (1966-76). For instance, posters which appeared in Peking (later to be called Beijing) in 1966, openly called for the abolition of Islamic practices. Muslims were also barred from learning their written language which incorporated the Arabic script and was influenced by Arabic, Turkish and Farsi. This change was critical as it distanced Muslims from the Arabic language, the language of the Qur’an and their Islamic aspirations. During this era many Mosques were closed down and waqf properties were confiscated. (Yusuf Abdur Rahman)
Since religious freedom was declared in 1978, the Chinese Muslims have not wasted time in expressing their convictions. There has been an increased upsurge in Islamic expression in China, and many nationwide Islamic associations have been organized to coordinate inter-ethnic activities among Muslims. Islamic literature can be found quite easily and there are currently some eight different translations of the Qur’an in the Chinese language as well as translations in Uygur and the other Turkic languages (Yusuf Abdul Rahman). There are now some 34,000 mosques and 400 Islamic organization in the entire People’s Republic of China (Beijing, Rabi Awwal 28/June 20 (IINA). Muslims are allowed to perform Hajj and the number of pilgrimage from China is about 3000 per year.
At present, according to official statistics there are 28 million Muslim in China but in 1936 it was estimated that the Muslim population was 48 million. By this time total population has increased 3-4 fold. So we can conclude that the total Muslim population has increased minimum by that same proportion. Therefore, now the total Muslim population is at least 150 million.