A semiconductor system may include a first semiconductor device including a first pad, a second pad and a first test input pad, and suitable for storing data inputted in series through the first test input pad and outputting the stored data in parallel through the first pad and the second pad; a second semiconductor device including a third pad, a fourth pad and a second test output pad, and suitable for storing data inputted in parallel through the third pad and the fourth pad, a first through via connecting the first pad and the third pad so that the stored data outputted in parallel through the first pad is inputted in parallel through the third pad; and a second through via connecting the second pad and the fourth pad so that the stored data outputted in parallel through the second pad is inputted in parallel through the fourth pad.