Nowadays refractory or relapsed leukemia/lymphoma lacks effective treatment. Innovative therapy is urgently required. Chimeric antigen receptor (CAR)-modified T cells have demonstrated great successes in treating even late stage cluster of differentiation antigen 19 (CD19) positive B cell malignancies. To design better CAR T cells, we have developed new CD19 CARs. Preclinical studies have demonstrated effective killing of CD19 target cells. In this study, the CD19 CARs, will be evaluated in CD19 positive leukemia/lymphoma patients. The primary goal is to confirm its adverse effects including cytokine storm response and any other adverse effects. In addition, tumor targeting and disease status after treatment will also be evaluated.