Organics are important impurity in Bayer alumina production process. Organics has the greatest impact on particle size and strength of product.The impact of organic impurity on sodium aluminate solution was studied from three aspects in this paper: 1) Analysis of distribution of organics in sodium aluminate solution, and the distribution of organics were quantified in different units.2)Comparative experiments with different single LMW organics were finished, and the impacts of each organic matter on precipitation indexes was quantitatively discussed. 3)Comparative tests of two sodium aluminate solution, pregnant liquor from plant containing organic impurity and pure pregnant liquor, were done with different temperature schedules, and precipitation yield and particle size were quantified. The distribution of organics in the sodium aluminate solution was initially mastered, and the impact of LMW organics was quantified. Meanwhile，an optimized temperature schedule was identified for the sodium aluminate solution containing organics.