Abstract: One-dimension spatial resolution soft X-ray spectra of laser-produced Ta plasmas is obtained by using a bent crystal spectrometer. Some resonance transition of the type 4f-3d in the Ni and Co-like isoelectronic sequence are identified. The Ni -like isoelectronic sequence wavelengths and Co-like 4f-3d resonance transition possible value are introduced. Wavelengths are measured with an uncertainty of ±5×10-5 nm。