Objective: To analyze the correlation between the qualitative characteristics and quantitative analysis of contrast enhanced ultrasound (CEUS) and the expression of Ki-67 in cervical metastatic lymph nodes of non-small cell lung cancer (NSCLC).SMethods From June 2021 to July 2022, 125 patients with NSCLC in Yichang Central People"s Hospital were selected for retrospective study. Finally, 60 cervical metastatic lymph nodes of 52 patients with NSCLC confirmed by biopsy and pathology were included. According to the expression of Ki-67 in lymph nodes, they were divided into high expression group (Ki-67≥30%) and low expression group (Ki-67＜30%). The ultrasound characteristics of lymph nodes in the two groups were compared,including CEUS qualitative characteristics (perfusion mode and perfusion type) and CEUS quantitative parameters of medulla Central and surrounding areas.They were analyzed to discuss the ability of CEUS quantitative parameters to predict Ki-67 expression level.Results The peak intensity (PI), perfusion velocity (C) of CEUS quantitative parameters in the whole lymph node and central area with the PI of peripheral area in Ki-67 high expression group were higher than those in low expression group (all P＜0.05). The blood flow (AUC) of central area of lymph nodes in Ki-67 high expression group was higher than that in low expression group (P＜0.05), and there was no significant difference in AUC of periperal area between the two groups. AUC and C in central region of lymph nodes were positively correlated with Ki-67 expression (all P＜0.001). The area under ROC curve of central region AUC and C predicting Ki-67 expression was 0.8440 and 0.9001, respectively. There was no significant difference between the two groups in the conventional ultrasound characteristics and CEUS qualitative characteristics of lymph nodes (all P＞0.05). Conclusion The CEUS quantitative parameters AUC and C in central region of cervical metastatic lymph nodes of NSCLC can predict the expression level of Ki-67, which is helpful to evaluate the tumor biological characteristics of NSCLC in a non-invasive manner.