ARHGAP family genes encode Rho/Rac/Cdc42-like GTPase activating proteins with RhoGAP domain. Here, we characterized human ARHGAP10 gene by using bioinformatics. Complete coding sequence of ARHGAP10 isoform A was determined by assembling nucleotide position 1-725 of FLJ41791 cDNA (AK123785.1) and 5'-truncated IMAGE4310652 cDNA (BC011920.2). Nucleotide position 240-2600 of ARHGAP10 isoform A was identical to GRAF2 cDNA (AB050785.1). Complete coding sequence of ARHGAP10 isoform B was derived from FLJ41791 cDNA. ARHGAP10 isoform A, consisting of exons 1-23, encoded full-length protein (786 aa). ARHGAP10 isoform B, consisting of exons 1-5 and intron 5, encoded C-terminally truncated protein (163 aa). ARHGAP10 gene was found encoding two isoforms due to alternative splicing. ARHGAP10 mRNA was expressed in chondrosarcoma, breast cancer, kidney tumors, and brain tumors. ARHGAP10 and ARHGAP26 (GRAF), showing 57.9% total amino-acid identity, shared the common-domain structure with BAR, PH, RhoGAP and SH3 domains. ARHGAP10-NR3C2 locus at human chromosome 4q31.23 and ARHGAP26-NR3C1 locus at human chromosome 5q31 were paralogous regions (paralogons) within the human genome. ARHGAP gene family was found consisting of at least 32 members, including ARHGAP1, ARHGAP2 (CHN1), ARHGAP3, (CHN2), ARHGAP4, ARHGAP5, ARHGAP6 (STARD8), ARHGAP7 (STARD12 or DLC1), ARHGAP8, ARHGAP9, ARHGAP10, ARHGAP12, ARHGAP13 (SRGAP1), ARHGAP14 (SRGAP2), ARHGAP15, ARHGAP17 (RICH1), ARHGAP18, ARHGAP19, ARHGAP20, ARHGAP21, ARHGAP22, ARHGAP23, ARHGAP24, ARHGAP25, ARHGAP26, STRAD13 (DLC2), HA-1, GMIP, PARG1, PIK3R1, PIK3R2, RACGAP1, and FNBP2. Genetic alterations of ARHGAP family genes lead to carcinogenesis through the dysregulation of Rho/Rac/Cdc42-like GTPases.