The purpose of this study is to improve the quality of white pan bread by adding polymannuronic acid, an excellent rheological properties material which has the high blood control function in seaweeds, to flour. To investigate the rheological properties appropriate to the making of white pan bread, amylograph, farinograph, extensography were done adding polymannuronic acid(0%, 1%, 3%, and 5%) to flour. The gelatinization condition between flour and compositic flour, amylogram was done. The result was that the gelatinization temperature in flour(100%) was $61.0^{circ}C$, as polymannuronic acid rate was increased by 1%, 3%, 5%, thetemperature was all the same, $63.5^{circ}C$. The maximum viscocity temperature of flour(100%) was $92.0^{circ}C$. that of flour added polymannuronic acid (1%) $92.5^{circ}C$, those of flour added polymannuronic acid (3%, 5%) unchangeable. $alpha$ -amylase activity degree, maximum viscocity was that flour(100% was 525 BU, flour added polymannuronic acid (1%) 498 B.U, flour added polymannuronic acid (3%) 385B.U, flour added polymannuronic acid (5%) 360 B.U, highly decreased. Farinograph was done, as the additional quantity of polymannuronic acid increase(1%, 3%, 5%), water absorption rate increase much more thin the control. As the additional quantity of polymannuronic acid is added from 1% to 3%, development time of dough was increase, but one added 5% was decreased. In case of extensograph was done, resistance of dough increased but extensibility is decreased, so R/E value increased.