Abstract: The dispersion of graphene oxide (GO) with organic dye rhodamine B (RhB) assisted polycarboxylic acid water reducer (PCE) and its effect on the strength and durability of cement mortar were studied. The dispersion of GO in saturated calcium hydroxide (CH) solution by RhB was studied by absorbance test, Zeta potential, and AFM characterization. The results show that the dispersion of GO in CH solution could be greatly improved when a small amount of RhB was added, and the dispersion effect of GO is the best when the mass ratio of GO to RhB is 1∶2. The mechanical strength test shows that the maximum increase of 28 days flexural and compressive strength are 14.78% and 33.29% respectively under the auxiliary dispersion of RhB compared with the GO mortar specimens without RhB, when the content of GO is 0.03wt% of the mass of cement. The durability test shows that RhB could promote the template effect of GO on cement hydration products, make the structure more compact, reduce the corrosion by freeze-thaw and sulfate, and significantly improve the durability. The microscopic test shows that the addition of RhB could promote the role of GO in more regulating the growth of hydration products, and the defects such as internal structure holes and cracks are significantly reduced. This work provides a method to introduce low-cost organic dyes to improve the dispersion performance of GO in cement pore solution, which has many potential applications.