Increasing concerns on animal welfare, the discussion about the necessity and the ethical acceptability of animal experiments is getting important. In this article, we describe ethical issues between the benefits of the animal experiments and the suffering of the animals. If there are no alternatives for animal experiments, the ethical guidelines, 3Rs (Reduction, Replacement, Refinement) by Russell and Burch for humane animal experiments should be considered. Moreover, Institutional Animal Care and Use Committee (IACUC) and Institutional Biosafety Committee (IBC) assist researchers to perform animal testing humanely and safely. We point out three important aspects in support of humane animal experiments; 1) the development of diverse scientific alternatives on the animal testing, 2) the ethical education of animal experiments for researchers, 3) the productive interactions among various social groups on ethics and safety of animal experiments.