Objective: To investigate the differences in 1H nuclear magnetic resonance (1H NMR)-based metabonomic analysis between oral squamous cell carcinoma (OSCC) and healthy control by principal component analysis (PCA); also, to evaluate this method in distinguishing different sample classes, and to detect the relationships between genotypes and phenotypes. Methods: 1H NMR resonances of plasmas were obtained from 20 OSSC subjects as well as 20 healthy subjects, and spectrally processed. Subsequent data were reduced by applying unsupervised PCA, one method of pattern recognition analysis, to detect the different spots corresponding to the low-molecular-mass metabolites. Results: Some important micromolecular species in plasma, including myo-inositol, praline, creatinine, arginine, and aspartic acid displayed great dissimilarity between OSCC and healthy control. Conclusion: The NMR metabonomic technique is feasible for studying the small molecule components of human blood plasma. Schlagwörter: 1H NMR spectroscopy, metabonomics, oral squamous cell carcinoma