This paper analyze the freedom of association in Japan, focus on why the union density is decreasing, the situation of collective bargaining and collective agreement, especially on union shop agreement, unfair labor practice, representative of employees, rights to organize labor union in case of public employees. First, about 90% of Japanese labor unions are enterprise-wise union supported by permanent employees, so the union density will be decreasing because the atypical employees is creasing. Second, although new academic opinion asserts that union shop clause shall be null and void because it will impair the individual worker’s right to choose labour union, but it still does not get support from majority of labour law researchers in Japan. In order to get speedy resolution under the 2004 Amendment of Labour Unions Act, and it do works. Speedy resolution can be achieved more than before. Majority representative is advocated to represent employees at the workplace involving regular and irregular workers, but labor unions object this scheme because it will obstruct worker’s right to organize labor unions. Finally, although DPJ had tries to grant trade union rights to public service workers, but Japanese public employees are still unable to have right to conclude collective agreement.