This invention is intended to provide cell aggregates that can reproduce functions of the myocardium, such as the function of beating, and thus are available for myocardial regenerative therapy, and to provide a cell culture support for producing the same.According to this invention, a cell culture support for forming string-shaped cardiomyocyte aggregates, which has a substrate portion having one surface on which at least one linear cell-adherent region is formed is provided.