In summary, we have demonstrated that direct chemical synthesis of oligos with over 1,000 nucleotides can be reliably achieved. The innovations that made this possible include conducting synthesis on smooth surface instead of within pores, and isolation of low percentage of full-length oligo from complex crude mixture using the powerful catching-by-polymerization (CBP) method. Conducting oligo synthesis on smooth surface not only reduced steric hindrance, but also drastically reduced errors. The latter is even more important than the former, and was beyond our expectation. The longest oligo synthesized in this work is the 1,728-mer Φ29 DNA polymerase gene. Given the high quality of data as demonstrated by gel electrophoresis and Sanger sequencing, we believe that the method reported here can be used to synthesize even longer oligos. Synthesizing 1,000-mer oligos has long been a major goal in the field of oligo synthesis. Now that this goal has been achieved, we anticipate that many projects in areas such as synthetic biology, protein engineering, CRISPR Cas 9 gene editing, and many others will become easier.