The narrow power decay width λq may lead to high heat flux density to the divertor target, which is one of the most severe challenges for future fusion devices. EAST has upgraded its lower graphite (C) divertor to a tungsten (W) one, and it is important to reveal the dependence of λq on the divertor condition. In the present work, SOLPS-ITER is applied to estimate the effect of various conditions [C/W plasma facing material (PFM), with/without drift] on λq of EAST in attached divertor regime. The simulation results confirm that the power decay width of the upstream λq,SOL, divertor λq,OT, and private-flux region (PFR) SOT all depend on the PFMs and drifts. However, the effect of PFM on λq,SOL is slight, while it has a significant influence on λq,OT and SOT. In the upstream, positive correlation between λq,SOL and is obtained, and the simulation is in qualitative agreement with the two-point model. Both λq,SOL and λq,OT in without drift case are larger than that of with drift case. The regression of simulation results is obtained, showing a strong positive correlation between SOL collisionality , power radiation friction in divertor region frad,OD and λq,OT. Thus, the C PFM with intrinsic impurity has the largest λq,OT. In the PFR, SOT with drift is smaller than that of without drift. Moreover, the combination of more D atoms accumulation and stronger Ep × B drift lead to larger SOT in W PFM case than that of C PFM case.