Abstract: Ubiquitous chromatin opening element(UCOE), composed of the promoters of human housekeeping genes, prevents transgene from silencing and produces consistent, stable and high-level gene expression irrespective of the chromosomal integration site. The research studied the influence of different UCOE element parts on antibody expression in CHO cells. UCOE 1. 5 kb from chromobox homolog 3(CBX3), UCOE 2. 5 kb from the heterogeneous ribonucleoprotein A2/B1(HNRPA2B1)and the whole UCOE 4. 0 kb were inserted into the antibody light and heavy chain vectors, respectively, and transfected into CHO cells using antibiotics-Zeocin and Blasticidin for pressure selection. Four groups of monoclonal cells were harvested and antibody expression of each group was detected. The monoclonal cells with UCOE 1. 5 kb and UCOE 2. 5 kb increased 1. 5 to 2-fold in the level of antibody expression, wheareas, monoclonal cells with UCOE 4. 0 kb increased 3 to 4-fold. The enhancement of two housekeeping promoter genes on antibody expression could stack up.