With the Sui dynasty overthrown and the Tang dynasty established,there appeared a tendency towards the integration of the Southern School and the Northern School,both concerned with Buddhism in China.Buddhism in the North was not well-digested when it was originally introduced from the south.It was excessively exact and elaborate and therefore difficult to be popularized.Buddhism in the south,however,was free and simple and most of the Zenists were common people in the countryside,who laboured in the fields.On the other hand,political changes took place and individual economy was developed in the South.These factors combined gradually made the Southern School be brilliant and outshine the Northern School.