In December 2020,the International Agency for Research on Cancer(IARC)released global cancer statistics that for the first time the incidence of breast cancer has surpassed lung cancer as the most common cancer worldwide.The incidence of breast cancer is increasing year by year.Surgical treatment is still the preferred treatment for early breast cancer,and whether regional lymph node metastasis is an important indicator to evaluate the prognosis of breast cancer.Sentinel lymph node is the first station of lymph node metastasis of breast cancer,so sentinel lymph node biopsy has replaced axillary lymph node dissection as a routine surgical treatment for early breast cancer.The key to the accuracy and success rate of sentinel lymph node biopsy is the choice of tracer.excellent sentinel lymph node tracers should include the characteristics of targeting,visibility,simple operation,low cost and few adverse reactions.In recent years,with the continuous improvement of technology,methods to search for sentinel lymph nodes have emerged in an endless fashion.Although the current guidelines point out that dye method combined with radionuclide method is the gold standard for sentinel lymph node biopsy.dye method is the dominant method in clinical practice due to many shortcomings of the nuclide method.At present,methylene blue injection is widely used as a tracer.Methylene blue injection has poor targeting ability to lymph nodes and it has certain limitations.With the development and improvement of the tracer,it was found that the carbon nanoparticles suspension had well lymph node taxis in sentinel lymph node biopsy.In order to provide reference for clinical applicationand and improve the accuracy and success rate of sentinel lymph node biopsy,the article introduce the characteristics,action principle,injection dose,development and adverse reactions of methylene blue and nano-carbon for comparison.