A complex [Mn(2,4-DAA)2(4,4'-bipy)]n with 2,4-dichlorophenoxy acetic acid and 4,4'-bipy has been synthesized and characterized. It crystallizes in the monoclinic space group C2/c with a=2.307 8(6) nm, b=1.164 3(3) nm, c=0.970 9(3) nm, β=96.249(5)°, V=2.593 2(12) nm3, Dc=1.668 g·cm-3, Z=4, F(000)=1 316, Final GooF=1.032, R1=0.046 1, wR2=0.110 2. The crystal structure shows that the complex forms a 2D layer structure by bi-dentate bridging 2,4-dichlorophenoxy acetic acid groups and 4,4'-bipy molecules. The manganese(Ⅱ) ion is coordinated with four oxygen atoms from four 2,4-dichlorophenoxy acetic acid molecules and two nitrogen atoms of two 4,4'-bipy molecules, respectively, giving a distorted octahedral coordination geometry. The luminescence property of the complex was also studied. CCDC: 674225.