And this period was also the period of the Tibet serf system coming into being, the revolution of productivity and the development of economy formed a firm fundament for the formation of the branches.

• 这也是西藏封建农奴制形成时期,生产力的变革、经济的发展为宗派的形成提供了充裕的物质条件。除了外界客观因素外,佛教自身的因素也是极其重要的。