A total of three thousand sample shell eggs (collected twice a month for one year from the five selected market channels) were evaluated to determine the seasonal variations of interior and interior egg quality. The results obtained are as follows ; 1. The price of market eggs way high in Spring (March-May) and Autumn (Sept-Oct), and low in Snmmer(Jun-Aug) and Winter(Nov-Jan). The maximum price spread was ±18% from the average price of the year. 2. Average egg shell thickness was 0.36㎜ with noticeable seasonal variation. It decreased to 0.33㎜ in Summer (Jun-Sep) while increased to above 0.36㎜ in the cool season of from Oct to March. Percent shell breakage was more closely related to environmental temperature than to ,hell thickness, resulting in the highest incidence of breakage in Winter due to freezing. 3. Haugh unit and yolk index showed wide seasonal variations ; 70 and 0.44, respectively, between Dec and Apr ; whereas 52 and 0.35, respectively, in .June and July when the environmental temperature was high and eggs were not moving fast through the market channels. 4. The pH value of whole egg also showed similar seasonal variation, ; 7.2-7.4 between Dec and Apr, while 7.8-8.0 from May to July and in Nov. Such a variation was closely related to the environmental temperature and the supply-demand of market egg. 5. To minimize the seasonal variation in egg quality, marketing system must be modernized with the improvement of handling facilities and the speedup of movement of egg, through the market channels.