ObjectiveTo investigate the diagnosis and treatment of familial hypokalemic periodic paralysis with acidosis. MethodsThe proband's medical history， clinical manifestations， laboratory examinations and imaging characteristics were retrospectively analyzed， and prevalence situation of family members was investigated in detail. Next generation sequencing technology was used to detect the pathogenic gene loci related to periodic paralysis， and the relevant literatures were summarized. ResultsThe proband was definitely diagnosed as familial hypokalemic periodic paralysis. There was a heterozygous mutation in the SCN4A gene of the proband， which was c.2006G>A， resulting in amino acid changes R669H.The proband's grandfather， father and uncle shared the same variation. ConclusionsFamilial hypokalemic periodic paralysis with paroxysmal acidosis is rare， which is easily misdiagnosed as renal tubular acidosis. c 2006G>A mutation in SCN4A gene is the molecular basis of the disease in this family. The clinical phenotypes of different gene mutations are different， and gene screening is helpful for diagnosis and treatment.