Marx’s interest rate determinism is based on an accurate grasp of the source and essence of interest. Marx revealed that interest is a part of the surplus value divided by capitalists who lend capital from capitalists who borrow capital. And profit is the transformed form of surplus value. This qualitative stipulation of interest determines its quantitative stipulation (this qualitative stipulation of interest determines its quantitative stipulation). The amount of interest depends on the total amount of profit. , the interest rate depends on the average profit rate. Marx further pointed out that between the average profit rate and zero, the level of the interest rate depends on two factors: first, the profit rate; second, the total profit is distributed between lenders and borrowers The ratio. The determination of this ratio mainly depends on the supply and demand relationship and competition between lenders and borrowers. Generally speaking, interest rates fall when supply exceeds demand; interest rates rise when supply exceeds demand. In addition, laws, customs, etc. also play a major role. Marx's theory It has guiding significance for explaining the issue of interest rate determination under the conditions of socialized mass production.