Introduction: Primary intestinal lymphangiectasia is a disorder characterized by exudative enteropathy resulting from morphologic abnormalities of the intestinal lymphatics. Intestinal Iymphagiectasia can be primary or secondary, so the diagnosis of primary intestinal Iymphagiectasia must first exclude the possibility of secondary intestinal Iymphagiectasia. Enteroscopy and biopsy, as well as the pathology can be used to confirm the diagnosis of intestinal Iymphagiectasia. A polymeric diet containing mediumchain triglycerids, total parenteral nutrition and Octreotid may be useful therapy. Case presentation: A 2-month-old male was admitted to the hospital with a history of diarrhea and edema. He was diagnosed with protein - losing enteropathy caused by intestinal lymphatics. This was confirmed by a enteroscopy and biopsy. After treatment with total parenetal nutrition and Octreotid in hospital, which was followed by a low - fat and medium triglyceride diet, he was totally relieved of his symptoms. Conclusion: Intestinal Iymphagiectasia can be diagnosed with enteroscopy and biopsy, as well as the pathology of small intestinal tissue showing edema of the submucosa and Iymphagiectasia. Because intestinal lymphagiectasia can be primary or secondary, the diagnosis of primary intestinal Iymphagiectasia must first exclude the possibility of secondary intestinal Iymphagiectasia. A positive clinical response to the special diet therapy, namely a low-fat and medium triglyceride diet, can further confirm the diagnosis of primary intestinal Iymphagiectasia.