Barium atoms pumped by a dye laser can absorb two photons and transit to high-lying states. By using a heat diode to detect ionization signals, we obtained three even-parity Rydberg series 6 ns 1S0(n=11～46), 6snd 1D2(n =9～60) and 6snd3D2 (n=10～28), as well as five perturbing levels 5d833D2, 5d83, 5d8s 1d2,5d7d 3F2, 5d7d3 P0 and 5d7d 1D2. The Lu-Fano plot is used in our discussion.