From June to July 2007, 36 cases of Guillain-Barre syndrome (GBS) occurred in a township in north China. Serological study and bacteria culture were performed to investigate the association between preceding Campylobacter jejuni infection and this GBS outbreak. Anti-C. jejuni antibodies were found in significantly higher numbers of GBS patients (IgM 84%, IgG 87.5%) than in healthy inspection cases (IgM 33%, IgG 27%). IgG anti-GM1 was the dominant anti-ganglioside antibody among the GBS patients. Seven C. jejuni isolates (four from human stool and three from poultry specimens taken from the patients' houses) were obtained. Serotyping and molecular analysis were used to investigate the genetic relatedness among these C. jejuni isolates. The four human isolates, collected from residents of the same district, were indistinguishable by both pulsed-field gel electrophoresis and multilocus sequence typing, suggesting these patients had a common source of infection. A new sequence type, sequence type-2993, was assigned to the human C. jejuni isolates, three of which belonged to Penner serotype heat-stable (HS):41. Both serotype and molecular subtype of the human C. jejuni isolates were different from those of isolates obtained from poultry specimens. Our results suggest that the antecedent C. jejuni infection triggered this GBS outbreak in China.