Magnetic properties of RPd2Al3 (R = Ce, Pr, Nd) system have been investigated by Al-27-NMR. An anisotropic hyperfine field A(ani) in the basal plane is negative for R = Pr and Nd, while A(ani) is positive for R = Ce, suggesting that f-p transferred hyperfine field contributes to the anisotropic Knight shift. From T-1 = constant relation, the exchange interaction for R = Pr is estimated to be 560 K and is much larger than that for R = Ce and Nd. It was found in PrPd2Al3 that NMR intensity and (T1T)(-1) decrease strongly near 30 K.