1. Allocation of funds and application amount: The National Natural Science Foundation of China receives a large number of applications for scientific research projects every year, but the available funds are limited. The setting of subsidy rate is based on the balance between the amount of funds available and the number of applications. According to the past experience and the planned budget, the funding rate of 5% was determined. We can control the use of funds while ensuring that certain funds are used to support scientific research in various fields.

2. Strict evaluation criteria and fierce competition: the project application of the National Natural Science Foundation has gone through a strict evaluation process, including expert evaluation and evaluation by the evaluation committee. Due to a large number of applications, evaluation criteria and competitive pressure, only some projects can be funded. The average annual funding rate is 5%, which means that the competition is fierce and only a few excellent research projects can get financial support.