The defection arrives a week after the Supreme Court sacked Emeka Ihedioha as Imo governor and declared Hope Uzodinma of the APC winner of the March 9, 2019 election.
Ihedioha is of the PDP.
The lawmakers making the switch to the APC are: Authur Egwim (Ideato North) from AA to APC; Chyna Iwuanyanwu (Nwangele), PDP; Chidiebere Ogbunikpa(Okigwe), PDP; Obinna Okwara(Nkwerre), AA; and Paul Emeziem (Onuimo) also from PDP to APC.
Others are Ekene Nnodimele (Orsu) from APGA to APC, Johnson Duru(Ideato South), AA; Ngozi Obiefule (Isu) AA; and Heclus Okorocha (Ohaji/Egbema) from PDP to APC.
House Speaker Collins Chiji read their letters of defection at the ongoing plenary.
The APC had no lawmaker in the 27-member Imo state house of assembly when Uzodinma was declared governor by the apex court.
More defections to the APC in the Imo parliament are likely to follow in the days ahead.
The PDP controlled the majority seats in the house before the defections.
Earlier, the Deputy speaker of the House, Okey Onyekanma, tendered his resignation from his position.