A compact dual-band bandstop filter with sharp-rejection using transversal signal- interaction, consisting of a transmission line path and a cascaded coupled line path, is proposed. Folded structure is used to decrease the size. By tuning the coupling coefficient and length, the centre frequency and bandwidth can be controlled, respectively. Meanwhile the transmission line impedance and odd-mode impedance can be used to improve the return loss and to allocate the transmission poles to sharp the attenuation rate, independently. A compact dual-band bandstop filter centring at 2.4 GHz and 3.7 GHz prototype is designed and fabricated to verify the validity. The simulation and measurement results agree well.