Abstract: Circulating material flow rate is an important parameter for the design and operation of circulating fluidized bed( CFB) boilers,but the hot-state in-situ measurements of it is still difficult. In the present study,the measurement method of circulating flow rate based on the heat transfer process was further improved. The effects on heat transfer coefficient between the high temperature solids and the tube surface were studied in hot state tests. The high temperature test data and the prediction model of the convective heat transfer coefficient proposed by Borodulya et al were used to establish the correlation between heat transfer coefficient and solid circulation rate. The results show that the influencing factors of the heat transfer coefficient include the solid circulation rate,particle temperature and the particle size. The error between the measured material flow rate and the preset value is within ±25%. The method can match the circulating material flow rate and heat transfer coefficient in pairs,and has good prediction in a wide range of flow rate. According to the research results,once the heat transfer coefficient is determined in the measurement,the solid circulation rate can be obtained by using the proposed model,and thereby the measurement of high temperature solid circulation rate is achieved. The heat transfer method is simple and has the advantages of low manufacturing cost. Based on the research,it has further improved practicability. It is a promising method of the measurement of circulating flow rate in CFB boilers.