The Ning-Wu Basin is the important component of the middle-lower Yangtze metallogenic belt. Based on detailed field geological works, the authors present new 40Ar-39Ar phlogopite ages for the typical Taocun, Baixiangshan and Hemushan iron deposits to constrain the timing and duration of mineralization in the basin. Phlogopite from the Taocun, Baixiangshan and Hemushan iron deposits yielded 40Ar-39Ar plateau ages of (129.3±1.1) Ma, (130.7±1.1) Ma and (129.1±0.9) Ma, respectively. The results indicate that different porphyry-like type iron deposits in the Ning-Wu Basin all formed in early stage of Early Cretaceous about 130 Ma, obviously later than skarn-porphyry Cu-Au deposits related to high-k calc-alkaline intrusions in uplift areas.