A novel light backscatter sensor is developed for continuous on-line monitoring of coagulation and syneresis to improve control level in milk production process or soybean production process.A math relation model was employed to study the effects of the macromolecules and the scattered light on production making parameters.The characteristics of light backscatter sensor was studied by experiment simulating production condition.The result showed that the light backscatter ratio and the average molecular weight ratio is the main factor of affecting protein coagulation process.The proposed technology shows potential for novel protein coagulation sensor developing and on-line monitoring.