To assess the feasibility of chromosomal microarray analysis(CMA) for studying the correlation between birth defects and chromosomal aberrations.A total of 2000 patients with birth defects were recruited for the CMA testing.Five hundred twenty two patients (26.1%) were found to have chromosomal abnormalities. These included 24 cases with numerical abnormalities, 11 with mosaicisms, and 11 with uniparental disomies. The remaining 476 cases were of well-known microdeletion or microduplication syndromes. The advantage of CMA over conventional karyotyping was demonstrated in many cases.As a powerful tool for patients with birth defects, CMA can produce a higher diagnostic yield compared with conventional karyotyping.