InAs dots were grown on anodized (0 0 1) GaAs substrates by molecular-beam epitaxy. It was found that InAs dots were selectively grown at the bottom of beehive-like etch-pits formed by anodization of GaAs substrates in an NH 4OH solution. The average size of InAs dots and its coefficient of variation on anodized substrates was larger than that on unpatterned substrates at the total amount of deposited In atoms less than about 4.0 ML, and vice versa at the deposited In amount of 10 ML. In the case of 10.0-ML InAs growth, one or two dots were grown at a bottom of beehive-like etch-pits on the anodized substrates, and the average size of InAs dots and its coefficient of variation on the anodized substrate were about two-third times smaller than those on the unpatterned substrate.