We have investigated the influence of Nd doping at La-site in La_2-xNd_xCa₁Ba₂Cu₅O_z (La-2125) (x = 0.0, 0.5, 1.0, 1.5, 2.0) system using X-ray diffraction (XRD), d. c. resistivity and iodometric titration studies. Rietveld analysis of XRD confirms the single-phase tetragonal structure with the space group P4/mmm for all the samples. Samples with x = 0.0 – 1.5 are superconducting with superconducting transition temperature, Tc ranging from 60 K to 38 K. Sample with x = 2.0 shows semiconducting behavior up to 39 K. It is interesting to note that T_c exhibit a strong correlation with increasing dopant concentration. The possible reasons for T_c suppression are discussed in this communication.