Developmental systems possess robustness, which is the ability to maintain phenotypic stability in the face of diverse perturbations arising from environmental changes, stochastic events, and genetic variation. But molecular signaling systems that control embryonic development are sensitive to these perturbations. Therefore, developing embryos should equip the mechanisms for overcoming the signaling perturbation during development. However, such mechanisms have been well understood. Here we show that early vertebrate embryonic tissues have an ability to eliminate signaling-perturbed cells. To investigate how embryonic tissues overcome the signaling perturbation, we mosaically induced Wnt signaling-hyperactivated cells in early zebrafish embryos. Interestingly, these mosaically-induced abnormal cells underwent apoptosis in wild-type embryos, but not in APC- or GSK3-inhibited embryos in which Wnt signaling is hyperactivated in entire tissues, indicating that signaling-perturbed cells are eliminated from normal embryonic tissues and this elimination requires the existence of normal cells. These results also suggest the possibility that embryonic cells may sense the difference of signaling activity in neighboring cells and make decision whether the neighboring cells should be eliminated. This cell elimination must be immune cell-independent event because early embryos don’t have immune cells. Importantly, Wnt signaling-hyperactivated cells-introduced normal embryos grew up almost normally, while inhibition of abnormal cell elimination severely disturbed embryonic development. It is suggesting that the signaling-perturbed cell elimination supports robustness of early vertebrate embryogenesis. Now we are exploring the detailed mechanisms that regulate the signaling-perturbed cell elimination. We’d like to show our recent progress of these studies.