Objective - To explore the clinical significance and mechanisms of altered miRNAs in squamous cell carcinoma of head and neck (SCCHN) and provide references for SCCHN diagnosis and prognosis. Method - Differential expressed miRNAs (DEMs) in SCCHN were screened through gene expression omnibus (GEO) DataSets and verified by the cancer genome atlas (TCGA) database. Next, the overall survival analysis, receiver operating characteristics, and clinical correlation analysis were adopted to filter the miRNAs with diagnostic and prognostic values. Finally, functional enrichment analyses were conducted for inquiring into the mechanisms of miRNAs. Results - Total 103 DEMs (p < 0.05, fold change >= 2) in SCCHN were screened out from GSE124566. Partly, the expression levels of the selected (12/17) miRNAs were verified by TCGA. Followed, of the 12 miRNAs, two miRNA expression levels were associated with the overall survival, and five miRNAs showed diagnostic values (AUC >= 0.85). Besides, miR-223-3p and miR-204-5p expression levels were correlated to certain clinical features. Epithelial-mesenchymal transition (EMT) related biological process and energy metabolism controlling related AMPK signaling pathway might mediate the roles of miR-223-3p and miR-204-5p, respectively. Conclusion - With diagnostic and prognostic values, miR-223-3p and miR-204-5p may be involved in the progression of SCCHN through EMT-related biological process and energy balance related AMPK signaling pathway, respectively.