Level of nitrogenous compounds in dried shellfish related to the formation of flavors during processing and storage was investigated. Fresh samples of blue mussel, short-necked calm and pacific oyster showed relatively low levels of ATP, ADP and AMP, but high levels of iMP and inosine. Relatively high content of TMAO in fresh samples was markedly reduced in the samples broiled samples, but TMA content was rather elevated in the samples broiled, which was a lowered result of TMAO content. The degree of reduction of TMAO and enhancement of TMA contents was relatively small in the hot-air dried samples during storage periods. Glycinebetaine content in fresh samples was slightly decreased by boiling and broiling. Contrast to glycinebetaine content, hormaline and trigonelline contents were severely reduced by boiling and broiling. Twenty-nine kinds of amino acids and their derivatives were identified in the sample of blue mussel, short-necked calm. Among them, glycine, alanine, arginine, glutamic acid and lysine were major amino acids, but contents of these amino acids was greatly decreased in the samples after drying and boiling processes.