The Tiananmen Square protests of 1989, also known as the June Fourth Incident in Chinese, were a series of demonstrations in and near Tiananmen Square in Beijing, China beginning on 15 April 1989.
In the late 1970s, the Chinese leadership of Deng Xiaoping implemented economic reforms, transitioning the nation from Maoist Communism into a "socialist market economy". By the late 1980s, grievances over inflation, limited career prospects for students, and corruption of the party elite were growing rapidly. Internationally, Communist governments were losing their grip on power in Eastern Europe. In April 1989, spurred by the death of deposed Communist Party General Secretary Hu Yaobang, mass gatherings and protests took place in and around Tiananmen Square. By 13 May there were over half a million protesters. The largely student-run demonstrations aimed for continued economic reform and liberalization, and eventually evolved into a mass movement for political reform and freedom of the press. Peaceful protests also occurred in other cities, such as Shanghai and Wuhan, while looting and rioting broke out in Xi'an and Changsha.
The movement lasted seven weeks after Hu's death on 15 April. Party authorities declared martial law on 20 May, but no military action took place until 4 June. Contrary to popular perceptions of the event, the violence did not occur during the protests on the actual square, but in the streets of Beijing, as the People's Liberation Army proceeded through the city to Tiananmen Square, using live fire, to clear the square of protestors. Major roles in sending the army to the protesters were played by Deng Xiaoping, Li Xiannian, Wang Zhen, Bo Yibo,Peng Zhen, Li Peng, and later, Yang Shangkun. The exact number of civilian deaths is not known, and the majority of estimates range from several hundred to thousands*.
Above articles are quoted from the video uploader and wikipedia.
*You can recognize casualties reported by the student organization in above Chinese article are from 2 or 3 thousand.
After the Tiananmen Square protests of 1989, Jiang Zemin (江沢民) strengthened ｐatriotic education ( = anti-Japan education) for their young people in '90s.
The number of victims in Nanjing has increased from 3 thousand (identified each by name at the time) to 300 thousand of nameless by the leadership of Jiang Zemin.
We, Japanese will never forget there were the Chinese people who fought for freedom and democracy and against the conservative dogmatists in1989.