Abstract: 　Objective　To explore the clinical feature and gene types in patients with primary carnitine deficiency. Methods 　Clinical data of 6 patients with primary carnitine deficiency and 2 patients with maternal carnitine deficiency found in the screening by tandem mass spectrometry technology during December 2013 to December 2016 were retrospectively analyzed. Results　The free carnitine levels of 8 patients in initial and recall screening were 5.85±1.65 μmol/L and 5.22±1.02 μmol/L. Two pathogenic alleles were detected in each patient with primary carnitine deficiency by genetic and metabolic disease panel based on Ion Torrent semiconductor sequencing. After treatment with oral L-carnitine, the free carnitine levels of 6 patients with primary carnitine deficiency were 20.24±3.88 μmol/L. The carnitine levels returned to normal after mixed feeding for one week in 2 patients with maternal carnitine deficiency, and no genetic diagnosis was carried out. Conclusion　Primary carnitine deficiency can be effectively detected using tandem mass spectrometry technology and next generation sequencing panel and the prognosis is good with early standard treatment.