Abstract: The present paper analyzed the factors influencing the products of the HRP-TMB reaction in the reticular nucleus located at inferior lateralis inferior oliver nucleus in mice using HRP-TMB-ST histochemical methods.1.The high pH-value (7.0 and above) was the most important element for the disappearance of reactive products;0.2 mol/L PB (pH5.0-6.0) was proper for the sensitivity of HRP-TMB reactions,the steadiness of the products and the reserve of histoultrastructures;when the pH-value was fixed,the degree and speed of product disappearances were dependent on the concentration of the buffer.2.The alcohol played an unnegligible role in stabilizing the products.3.Neither the component and concentration of the advanced soaking and perfusion solutions nor the fixation time was related to the disappearance of procucts.In addition,when the slices were further treated with DAB after rinsed with bufffers (pH5.5 and pH7.0),the products showed no significant differences at ultrastructural level.