Background: Chimeric antigen receptor T cells directed at CD19 (CART19) have shown promising results in the treatment of refractory/relapsed acute lymphoblastic leukemia and chronic lymphocytic leukemia. Evidence of efficacy on mass lesions such as extramedullary ALL and non-Hodgkin’s lymphoma is still emerging. Methods: Patient-derived T cells were transfected ex vivo with lentiviral vector encoding anti-CD19 scFv, human 4-1BB, and CD3ζ signaling domains. 2 patients with relapsed extramedullary ALL and 2 patients with relapsed DLBCL were enrolled (median age 25.5, range 17~35). Lymphodepletion regimens were fludarabine 50mg/m² infused over 3 days, and cyclophosphamide 750mg/m² infused over 3 days in DLBCL patients or over 2 days in ALL patients. CART19 were infused one time or fractionated over 3 days with dose from 1×10⁶/kg to 1×10⁷/kg. Results: The 2 ALL patients received prior allogenic HSCT; one relapsed with isolated testicular ALL, the other with mammary/axillary lymph node ALL with 15% blast cells in the bone marrow. The other two patients relapsed with DLBCL. After CART19 therapy, all patients achieved complete remission (CR) within a median of 30d (range 29~52d). With a median follow up of 53.5d (range 52~153d), the 2 DLBCL patients remained in CR; the testicular B-LBL patient relapsed with isolated testicular involvement on +153d and received a second CART19; the other B-LBL patient relapsed with isolated bilateral mammary glands involvement on +52d and remained in stable disease. Grade 2 cytokine release syndrome (CRS) were observed in the 2 DLBCL patients (50%). CRS self-resolved within 10d without treatment. Conclusions: CART19 was effective and safe against mass lesions such as relapsed extramedullary ALL and DLBCL with high CR rate. CART19 can induce rapid remission in lymphoma patients around one month.