(2) China semi-colonial and semi-feudal society is a society with two small ends and a big middle. The proletariat is sharply opposed to the landlord class and the big bourgeoisie, which account for only a minority of the population, while farmers, urban petty bourgeoisie and other middle classes account for the vast majority of the national population. If the proletariat in China wants to defeat the three enemies, it must unite with the industry, agriculture and petty bourgeoisie, which play an important role in the revolution, and form an alliance with the national bourgeoisie. (3) The imbalance, vacillation and long-term nature of China's revolutionary development determine that the proletariat and its political parties in China must use the United front strategy, unite all forces that can be United, mobilize a powerful revolutionary army, and promote the transformation of the balance of forces between the enemy and ourselves in favor of the revolution, thus fundamentally changing the situation that the enemy is strong and we are weak. (2) Possibility. There are complex contradictions in modern China society, which objectively provides the possibility for the proletariat and its political parties to use contradictions to establish and develop the United front. (2) The social nature and class relations of modern China also determined the possibility of establishing a broad United front in China.