Protein design holds promise for applications such as the control of cells, therapeutics, new enzymes and proteinbased materials. Recently, there has been progress in rational design of protein molecules, and a lot of attempts have been made to create proteins with functions of our interests. The key to the progress is the development of methods for controlling desired protein tertiary structures with atomic-level accuracy. A theory for protein folding, the consistency principle, proposed by Nobuhiro Go in 1983, was a compass for the development. Anfinsen hypothesized that proteins fold into the free energy minimum structures, but Go further considered that local and non-local interactions in the free energy minimum structures are consistent with each other. Guided by the principle, we proposed a set of rules for designing ideal protein structures stabilized by consistent local and non-local interactions. The rules made possible designs of amino acid sequences with funnel-shaped energy landscapes toward our desired target structures. So far, various protein structures have been created using the rules, which demonstrates significance of our rules as intended. In this review, we briefly describe how the consistency principle impacts on our efforts for developing the design technology.Key words: computational protein design, ideal proteins, funnel-shaped energy landscapes, consistent local and non-local interactions, Go modelUnderstanding of protein folding is important to develop the methodology for creating our desired proteins. Anfinsen hypothesized that proteins fold into the free energy minimum structures [1]. However, the folding problem-How do amino acid sequences determine the folded structures?has been a long-standing problem for more than a half century. Researches for protein folding or structure prediction from amino acid sequences have attempted to address the problem by studying complicated proteins created by nature spending billions of years, which have energetically unfavorable non-ideal features such as kinked α-helices, bulged β-strands and buried polar residues. Protein design studies provide an alternative approach to tackle the problem by creating simple protein structures not having such unfavorable features from scratch with hypotheses about protein folding and experimentally testing how the designs fold.Protein design expands the possibility of developments for therapeutics, biosensors, materials, etc. Recently there has been great progress in computational design of protein structures. The basic idea that underlies the progress is the rules we discovered relating secondary structure patterns to tertiary motifs, which make it possible to design Go's proposed ideal protein structures. In this review, we describe how our rules were discovered in the history of protein design and folding studies.