To explore the conventional cytogenetic (CC) characteristics and the partial molecular cytogenetic characteristics of multiple myeloma (MM), R banding technique was used for karyotype analysis in 53 cases of MM, and fluorescence in situ hybridization(FISH) technique was used for molecular cytogenetic analysis in 20 cases out of them. The results showed that the rate of chromosome abnormality was 32.1% in 53 cases. Among these abnormalities, 82.4% were involved in 3 or more than 3 chromosome aberrations, the mode of chromosome was from 44 to 90. The chromosome karyotype abnormality was involved in all of 24 chromosomes, and 70.6% chromosome aberrations involved at least one of 1q21 amplification, 13q14 deletion, 17p13 deletion and 14q32 translocation. Some uncommon structural aberrations were observed, such as t(11;16)(p11;p13) and some chromosome abnormalities were often revealed in acute or chronic leukemia. FISH detection showed that the results of 3 in 12 cases of MM with normal karyotype were positive; the results of 5 in 8 cases of MM with abnormal karyotype were positive. It is concluded that the abnormal chromosome karyotype was relatively complex in most cases of MM showing obvious heterogenicity. Detected rate of chromosome abnormalities in MM can be raised by FISH, though FISH technique has its limitations. If CC analysis and FISH technique are combined, it will be useful to raise the identification capability in detection of abnormal chromosomes in the cytogenetic study of MM.