A filled polymer composition comprises (i) an ethylene/.alpha.-olefin interpolymer, and (ii) a filler. The ethylene/.alpha.-olefin interpolymer is a block copolymer having at least a hard block and at least a soft block. The soft block comprises a higher amount of comonomers than the hard block. The block interpolymer has a number of unique characteristics disclosed here. The filled polymer compositions provided herein, in certain embodiments, have relatively higher heat resistance and improved noise, vibration and harshness properties and can be used in automotive floorings, roofings, wire and cable coating applications.