To explore the expression of CD4(+), IL-17 and Foxp3 in non-small cell lung cancer (NSCLC) and their relationship with microvessel density (MVD).The expressions of CD4(+), IL-17, Foxp3, CD31 and CD34 in the cancer tissues of 102 NSCLC cases were detected by immunohistochemisty. The relationship among the expressions of CD4(+), IL-17, Foxp3 and MVD was analyzed. The count data were analyzed using χ(2) test. The measurement data were analyzed using single-factor analysis of variance, and significance level α = 0.05.Among the factors affecting CD31 expression, there was a statistically significant difference between the strong positive Foxp3 expression (++) and negative (-) and positive expressions (+) in the NSCLC cancer tissues (P < 0.05), and between the expressions in stage I and III cancer tissues (P < 0.05). Among the factors affecting CD34 expression, there was a significant difference between positive IL-7 expression (+) and strong positive IL-7 expression (++) (P < 0.05), between negative Foxp3 expression (-) and strong positive Foxp3 expression (++) (P < 0.05), and between the CD34 expressions in stage I and III and between those in stage II and III NSCLC cancer tissues (P < 0.05).CD4, IL-17and Foxp3 may be involved in the tumor suppression caused by host immune response, and are related with the NSCLC invasion and metastasis.