Rosin was used as a raw material to prepare N-(3-rosin acyloxy-2-hydroxyl) propyl-N,N diethanolamine. First, rosin was modified with epoxy chloropropane. Then the modified rosin reacted with diethanolamine and N-(3-rosin acyloxy-2-hydroxyl) propyl-N, N diethanolamine was produced under the following conditions: modified rosin and diethanolamine mole ratio of 1:2, reaction temperature of 78°C, and reaction time of 2.5 h. The chemical structure of the product as a rosin amide derivative was identified by Fourier transform infrared spectroscopy (FTIR) and liquid chromatography-mass spectrometry (LC-MS) method. The anti-fungal activity of this rosinyl tertiary amine was determined in vitro against wood decay fungi, Trametes versicolor, Gloeophyllum trabeum and mould fungi, Aspergillus niger and Paecilomyces variot Bainier. The anti-fungal experiment results signified that N-(3-rosin acyloxy-2-hydroxyl) propyl-N,N diethanolamine was active to these fungi at a certain concentration.