This paper proposes a new physical method for measuring FeO content of agglomerate.Instead of commonly used chemical analytical method having a long retardative time.proposed method accomplishes in-line measurement of FeO content of agglomerate.Attention is mainly paid to the sensor (?) and its working principle.A microcomputer measuring system is also presented.The results show that this system has achieved successful in practice. This paper proposes a new physical method for measuring FeO content of agglomerate. Instead of commonly used chemical analytical method having a long retardative time. Proposed method accomplishes in-line measurement of FeO content of agglomerate. Attention is mainly paid to the sensor (?). and its working principle. A microcomputer measuring system is also presented. The results show that this system has achieved successful in practice.