A modified conjugated diene rubber is disclosed. A method for producing the modified conjugated diene rubber includes providing an alkali metal ion-containing conjugated diene rubber; and reacting the alkali metal ion-containing conjugated diene rubber with an alkoxysilane to generate the modified conjugated diene rubber, the alkoxysilane being of the structural formula: wherein R1, R2, R3 are each independently selected from a group consisting of oxygen-containing C2-C12 group and nitrogen-containing C3-C12 group, the oxygen-containing C2-C12 group has a carbon atom directly connected to oxygen atom of the alkoxysilane, the nitrogen-containing C1-C12 group has a nitrogen atom directly connected to oxygen atom of the alkoxysilane, and R4 is selected from a group consisting of C3-C12 of alkyl, alkenyl, aryl, and alkoxy.