Spinal muscular atrophy (SMA) is one of the most common fatal autosomal recessive genetic disorders among infants. It is caused by mutations of motor neuron survival gene 1 (SMN1). The incidence of SMA among newborns is approximately 1/10 000 - 1/6000, and the carrier rate is 1/72 - 1/47 with an ethnic variance. Based on the time of onset and clinical phenotype, SMA can be divided into types I - IV. Approximately 95% of SMA patients have carried homozygous deletions of exon 7 of the (SMN1)] gene. For its significant phenotypic difference, abundant changes of (SMN1)] gene copy number, presence of pseudogene interference and high carrier rate, early diagnosis, genetic consultation, treatment and prevention of SMA can be difficult. This guideline summarizes the relevant research, guideline and consensus issued at home and abroad, clinical manifestations and pathogenesis of SMA patients, and experience in its diagnosis and genetic counseling, with an aim to promote a standardized diagnosis and treatment and reduce the births of children affected with the disease.