This study was purposed to detect the minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) by using real time quantitative PCR (RQ-PCR) . The Ig and TCR gene rearrangements were amplified by using 18 primer sets in B-ALL, 8 primer sets in T-ALL; the ALL-MRD levels were quantified by using RQ-PCR with SYBR green dye staining and clone specific Ig/TCR gene rearrangements as molecular markers. The results indicated that there were 8 cases showing gene rearrangements in 9 B-ALL patients, marker detection rate for all samples was 88.8%, the MRD level on day 33 during induction treatment decreased significantly. It is concluded that Ig/TCR gene rearrangements can be used as a marker to detect MRD in childhood ALL; the technique of QR-PCR with SYBR green dye staining is reliable, relatively sensitive and easy performable method which can be used in routine detection for childhood ALL.