The invention relates to laevorotation lactone specificity hydrolytic enzyme producing strain and the method used it to make chirality oxyacid. The enzyme producing is Fusarium proliferatum NirenbergECU2002 with storage number CGMCC 1494. The chirality oxyacid preparing method includes the following steps: using the fungous mycelium, rough enzyme extract or their immobilization derivative as biocatalyst; processing antipode selectivity hydrolysis resolution for a series of racemic chirality lactone to gain many optically active (+)-oxyacid and (+)-lactone which can be hydrolyzed into (-)-oxyacid; (+)-alpha-hydroxyl-beta, beta-dimethyl-gamma-butyric acid which are D-(+)-pantoic acid; simple acidizing to gain chirality intermediate D-(-)-pantoic acid lactone widely used in preparing feed and daily chemical engineering industry.