目的　探讨小儿急性淋巴细胞白血病 (ALL)微量残留病 (MRD)检测的临床意义 ,进一步了解ALL复发与缓解的生物学特点。方法　分析近 10年来有MRD检测资料的 77例初治ALL ,对其中 4 4例进行动态追踪检测MRD。主要采用聚合酶链反应 (PCR)方法 ,以免疫球蛋白重链和T细胞受体δ基因重排作为肿瘤标志。结果　初治标本PCR检测MRD阳性者和阴性者的复发率差异无显著性意义 (P >0 0 5 )。化疗 3个月时PCR检测转阴的病例复发率明显低于未转阴的病例 (P <0 0 5 ) ,且与临床分型无明显相关性。结论　MRD的动态检测可以作为小儿ALL判断预后的独立因素。PCR法动态监测MRD ,有助于完善白血病分型、判断预后和指导治疗。 Objective To investigate the clinical significance of detection of minimal residual disease (MRD) in children with acute lymphoblastic leukemia (ALL) and to further understand the biological characteristics of ALL with relapse and remission. Methods 77 cases of newly diagnosed ALL with MRD test data in the past 10 years were analyzed, of which 44 cases were followed up for MRD. Polymerase chain reaction (PCR) was used as the tumor marker mainly based on immunoglobulin heavy chain and T cell receptor δ gene rearrangement. Results There was no significant difference in the recurrence rate between the newly diagnosed specimens and the negative specimens (P> 0.05). The relapse rate of negative PCR detection in 3 months after chemotherapy was significantly lower than that in non-negative cases (P <0.05), and had no significant correlation with clinical classification. Conclusion The dynamic detection of MRD can be used as an independent prognostic factor in children with ALL. PCR dynamic monitoring of MRD, contribute to improve leukemia typing, prognosis and guide treatment.