Neonatal inherited metabolic disorders are diverse and complex in etiology. Some inherited metabolic disorders are asymptomatic at birth, such as phenylketonuria and congenital hypothyroidism, while others may have symptoms such as feeding difficulties and facial changes. Neonatal inherited metabolic disorders are diverse and complex in etiology. Most of them are single-gene disorders, partly caused by inborn gene inheritance and partly originated from acquired gene mutation. Some of the inherited metabolic diseases may not have any clinical symptoms in the early stage, such as phenylketonuria and congenital hypothyroidism, and as the disease progresses, special facial features, growth retardation and mental defects may appear. There are also some inherited metabolic disorders, in which feeding difficulties, poor appetite, severe vomiting, weight loss, lethargy, hepatosplenomegaly, acidosis, peculiar facial features, abnormal eye spacing, deafness, and unresponsiveness are present right after birth, which often suggests that the condition is critical and the prognosis is unsatisfactory. When a child is suspected of having an inherited metabolic disease, timely consultation should be made to clarify the cause of the disease and adopt targeted treatment.