The invention relates to a kind of soya sauce containing organic selenium from aspergillus oryzae and preparation method, wherein the organic selenium is selenium salt originated from aspergillus oryzae, the selenium content in the soy sauce is 0.1-10mg/Kg. The preparation comprises using soy bean as raw material, making soy sauce yeast, preparing selenium-containing mother liquid and charging the yeast, inoculating the aspergillus oryzae, during fermentation, the aspergillus oryzae transforming inorganic state selenium into organic selenium in the cell, releasing the organic selenium and other nutritional substance through thallus autolysis, drenching oil to obtain the soya sauce containing organic selenium.