Objective To investigate the drug distribution in tissues of cervical lymph node metastasis mice model after submucosa adjacent cancer injection of pingyangmycin-activated carbon nanoparticles（PYM-CH-NP） and evaluate the lymph targeting effect of PYM-CH-NP. Methods Pingyangmycin（PYM） was radiolabeled with 125I by modified the chloramine T method. Cervical lymph node metastasis mice model was established by buccal submucosa inoculation of a high lymph metastasis cell line U14 cancer cell. 360 mice models burdened with cervical lymph metastasis were randomly divided into 3 groups. PYM group was treated with PYM water solution, PYM-CH-NP group was treated with PYM-CH-NP. Negative control group was injected with activated carbon nanoparticles. PYM-CH-NP and pingyangmycin water solution were injected in pericancer submucosa of the mice respectively. The radioactivity of drug in blood, heart, liver, spleen, lung, kidney and cervical lymph node were measured after 0.5, 1, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168 h administration. The radioactivity of each samples per unit weight were calculated. The selectivity index（SI）and targeting index（TI） of drug were calculated. Results The radioactivity of drug in cervical lymph node of PYMCH- NP group was much higher than PYM group in each time point（P
