ABSTRACT: Among urochordates (tunicates)âthe closest living relatives of vertebratesâCiona intestinalis is increasingly being used as a model organism in the field of developmental biology. Ciona intestinalis is the seventh animal which genome published; the ~120-Mbp euchromatin region is estimated to contain ~16,000 protein-coding genes. In addition, analyses of more than one million ESTs have provided the foundation for gene models and associated transcriptomes. The fertilized Ciona intestinalis egg develops into a tadpole larva with a simplified chordate body plan, and then it metamorphose into adult sea squirt of sessile filter feeder. One of interests in the field of developmental biology is to understand what kind of genes are expressed in the body and how spatially and/or temporally coordinated expression of genes is controlled. In this study, we investigated the entire gene expression of 11 organs of adult Ciona; the neural complex, branchial sac, esophagus, stomach, endostyle, intestine, body-wall muscle, heart, blood cells, ovary, and testis. Our data would provides basic information of transcriptome in each organ and help to understand gene expression control of organ specific genes. Gene expressions in 11 organs of adult Ciona intestinalis; blood cells, branchial sac, digestive grand, endostyle, esophagus, heart, body-wall muscle, neural complex, ovary, stomach and testis. Three independent experiments were performed at each tissue using different individuals for each experiment.