Recent Theoretical Developments on Atomic Data for Fe L-shell Ions  Ming F. Gu Stanford University 382 Via Pueblo Varian 334 Stanford, CA 94305 Emission lines from L-shell ions of iron dominates the soft X-ray spectral band for hot collisionally-ionized plasmas with tempeparatures near $10^6$ K. These lines also contribute significantly in the spectra of photoionized plasmas. To accurately model such spectra, a large set of atomic data is needed, including wavelengths, radiative transition rates, collisional excitation, radiative and dielectronic recombination rates, and collisional ionization. We review the recent theoretical efforts in producing such atomic parameters and assess their accuracy by comparing with the experimental measurements wherever available. We also compare the close-coupling and distorted-wave theoretical approaches in treating the collisional excitation and recombination of Fe L-shell ions.