The concept of ζεινο&b.sigmav; is not so clear. ζεινο&b.sigmav; is usually understood in two divided meanings, A. guest-friend, B. stranger. People interested in this word have sought the development of this word. However, considering that already in Homer both meanings are found, it must be treated as one word which has the two meanings at the same time. Also whether it has any united meaning must be investigated. In this paper the author intends to clarify the concept of ζεινο&b.sigmav;. At first he examines the opinion of Ph. Gauthier who first tried to understand its united meaning ("Notes sur l'etranger et l'hospitalite en Grece et a. Rome," Anc. Soc. 4, 1973). Gauthier insists that ζεινο&b.sigmav; is another Greek. The author finds some difficulties in this theory, and concludes that his opinion does not have grounds for support. For example, his insistence that αλλοθροοι cannot be ζεινο&b.sigmav; contradicts the material suggesting that Egyptians, who seem to be αλλοθροοι, can be ζεινο&b.sigmav;(Od. XIV. 283-6). The other evidences do not suggest the necessity of dividing Greeks and non-Greeks, either. Then the author studies the use of ζεινο&b.sigmav; in archaic times, especially in Homer, in which it is used 208 times. He draws these conclusions: 1. The meaning of ζεινο&b.sigmav; is constant in showing the people who do not belong to the same community. 2. Estimates of ζεινο&b.sigmav; are in a certain range. 3. There exists μεταναστη&b.sigmav; who cannot be ζεινο&b.sigmav; for a long time. His estimate is low. 4. A non-μεταναστη&b.sigmav; foreigner can remain ζεινο&b.sigmav; much longer than μεταναστη&b.sigmav;, but not forever. 5. In any case the period of remaining ζεινο&b.sigmav; links the degree of his estimate. These point out that ζεινο&b.sigmav; can be understood from two factors, estimate and time. The author, thereupon, presents the figure of ζεινο&b.sigmav;-concept by making two axes, estimate and time. From this concept-figure the author throws some new light on the dogma that a foreigner at this time was without legal rights. Foreigner should be understood strictly by names, because ζεινο&b.sigmav; is not foreigner in general. Since Odysseus can claim his rights as ζεινο&b.sigmav; to Cyclops(Od. IX. 266-71) , and themis orders that ζεινο&b.sigmav; should be given hospitality, ζεινο&b.sigmav; must not be without legal rights. μεταναστη&b.sigmav;, however, appears as without legal rights, because, who, when he wants to stay there, needs to change in a short time into some concept other than ζεινο&b.sigmav;, such as θεραπων, θη&b.sigmav;, cannot claim his rights as ζεινο&b.sigmav; for a long time. If he does, it means that he will have to leave that place in a short time and return to a wandering life again. Remaining ζεινο&b.sigmav; any longer than the period determined by the degree of his estimate, will cause dissatisfaction among people and he will not be able to expect hospitality any more as in the case of Odysseus who returned to Aeolus (Od. X. 725). To understand ζεινο&b.sigmav; from these two factors, estimate and time, is not helpful in understanding that of classical times. The structure of ζεινο&b.sigmav;-concept suffered a great change during the development of polis. The essence of this change will be clearly understood when the structure of ζεινο&b.sigmav;-concept in classical times is well grasped.