1, ancient Greece had many mountains, many islands, many good ports, few plains and poor land. A small piece of land separated by mountains, seas and waters has formed a city-state system characterized by small countries and few people (the main factor), and it is easy to implement a democratic system. At the same time, a small city-state with few people needs to strengthen its cohesion through democracy to ensure its independence and development and safeguard the main position and interests of slave owners. It also leads to the development of commodity economy, and it is easy to form the values of equality, mutual benefit, honesty, equality, democracy and openness. At the same time, it makes the emerging industrial and commercial class rise and pursue democratic rights urgently.

2. The unremitting efforts of politicians and the struggle of civilians, especially the emerging industrial and commercial class.

3. The development of slavery economy provided it with necessary material guarantee.

4. Influenced by the democratic habits of primitive society and Asian-African civilization.

Impact:

1, which promoted the overall prosperity of Greece, made ancient Greece achieve brilliant achievements in many cultural fields and became the cradle of western culture.

2. Created western democratic politics, and its thoughts and practices (sovereignty belongs to the people, taking turns to govern, equality of citizens, supremacy of law, separation of powers and other democratic operation modes such as differential election system, term system, parliamentary system and proportional representation system) laid a preliminary foundation for modern western democratic political system.