Serum samples from non-Hodgkin lymphoma (NHL) patients who had not undergone chemotherapy, lymphnoditis patients, and healthy adults were analyzed using surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF MS) to detect the differentially expressed serum proteins. Models were developed to distinguish between the healthy adult group and the NHL group, with a sensitivity of 69% and specificity of 90%, and between the lymphnoditis group and the NHL group with a sensitivity of 74% and specificity of 84%. A protein with the m/z of M10 197.91 u was expressed at a significantly higher level in the NHL group, compared to the other groups. Furthermore, differences were also significant among different stages of NHL and among samples with different International Prognosis Index (IPI) scores or lactase dehydrogenase (LDH) levels. The three identified proteins may offer a new serological approach for early diagnosis, differential diagnosis, and pathogenic investigation of NHL. And the protein with the m/z of M10 197.91 u may be a new serological biomarker for monitoring treatment response and evaluating the prognosis of patients with NHL.