Abstract: Cattle Smad4 gene cDNA was cloned by RT-PCR, 3' RACE and 5' RACE and got a 3 503bp full-long cDNA sequence. The cloned cattle Smad4 cDNA sequence had been send to GenBank and got a accession number: DQ494856. Cattle Smad4 gene consists of 12 exons and codes 553 amino acids. Cattle Smad4 cDNA shares 99％, 96％, 95％, 91％, 91％ similarity in nucleic acid sequences and 99％, 98％, 98％, 99％, 98％ similarity in amino acid sequences with sheep, pig, human, rat and mouse respectively. Smad4 cDNA was found in testis, pancreas, liver, small intestine, ovary, lymph, cardiac muscle, skeleton muscle and thymus gland, this indicated Smad4 is broad expressed in cattle.