NOVELTY - Catalyzing temsirolimus synthesis by enzyme, comprises reacting rapamycin with 5-methyl-(1,3)dioxane-5-carbaldehyde (I) in solvent under action of hydrolase to obtain substituted compound temsirolimus (II) and performing normal de-protection reaction in substituted rapamycin to obtain temsirolimus, where the hydrolase is protease, lipase or acyltransferase.    USE - The method is useful for catalyzing temsirolimus synthesis by enzyme, which is useful for treating kidney tumor. No biological data given.    ADVANTAGE - The method is capable of conveniently and safely catalyzing temsirolimus synthesis by enzyme with high yield in an economical manner.    DETAILED DESCRIPTION - Catalyzing temsirolimus synthesis by enzyme, comprises reacting rapamycin with 5-methyl-(1,3)dioxane-5-carbaldehyde of formula (I) in solvent under action of hydrolase to obtain substituted compound temsirolimus of formula (II) and performing normal de-protection reaction in substituted rapamycin to obtain temsirolimus, where the hydrolase is protease, lipase or acyltransferase.    X = SR1, SC5H4N, OC6H5, OC6H4R1, OC6H4OH, OC6H4OR1, OC6H4CH=CH2, OC6H4NH2, OC6H4NHR1, OC6H4NR2R5, OC6H4CONH2, OC6H4CONHR1, OC6H4CONR2R5, OC6H4W1, OC6H3W2, OC6H2W3, OC6H4CHO, OC6H4COR1, OC6H4COOR1, OC6H4NO2, OC6H3(NO2)2, OC6H2(NO2)3, OC6H3(W1)(NO2), OCnH2nOC6H4NO2, OCnH2nOC6H3(NO2)2, OCnH2nOC6H2(NO2)3, OCnH2nOC6H3(W1)(NO2), OCnH2nOCOC6H4NO2, OCnH2nOCOC6H3(NO2)2, OCnH2nOCOC6H2(NO2)3, OCnH2nOCOC6H3(W1)(NO2), OC10H6NO2, OC10H5(NO2)2, OC10H4(NO2)3, OC10H5(W1)(NO2), OCnH2nOC10H6NO2, OCnH2nOC10H5(NO2)2, OCnH2nOC10H4(NO2)3, OCnH2nOC10H5(W1)(NO2), OCnH2nOCOC10H6NO2, OCnH2nOCOC10H5(NO2)2, OCnH2nOCOC10H4(NO2)3, OCnH2nOCOC10H5(W1)(NO2), OC6H4OR1, OC6H3(OR1)2, OC6H2(OR1)3, OC6H3(W1)(OR1), OCnH2nOC6H4OR1, OCnH2nOC6H3(OR1)2, OCnH2nOC6H2(OR1)3, OCnH2nOC6H3(W1)(OR1), OCnH2nOCOC6H4OR1, OCnH2nOCOC6H3(OR1)2, OCnH2nOCOC6H2(OR1)3, OCnH2nOCOC6H3(W1)(OR1), OC10H6OR1, OC10H5(OR1)2, OC10H4(OR1)3, OC10H5(W1)(OR1), OCnH2nOC10H6OR1, OCnH2nOC10H5(OR1)2, OCnH2nOC10H4(OR1)3, OCnH2nOC10H5(OR1), OCnH2nOCOC10H6OR1, OCnH2nOCOC10H5(OR1)2, OCnH2nOCOC10H4(OR1)3, OCnH2nOCOC10H5(W1)(OR1), SC6H4NO2, SC6H3(NO2)2, SC6H2(NO2)3, SC6H3(W1)(NO2), OCnH2nSC6H4NO2, OCnH2nSC6H3(NO2)2, OCnH2nSC6H2(NO2)3, OCnH2nSC6H3(W1)(NO2), OCnH2nOCSC6H4NO2, OCnH2nOCSC6H3(NO2)2, OCnH2nOCSC6H2(NO2)3, OCnH2nOCSC6H3(W1)(NO2), OC6H4CF3, OC6H3(CF3)2, OC6H2(CF3)3, OCnH2nOC6H4CF3, OCnH2nOC6H3(CF3)2, OCnH2nOC6H2(CF3)3, OCnH2nOCOC6H4CF3, OCnH2nOCOC6H3(CF3)2, OCnH2nOCOC6H2(CF3)3, OC6H4CN, OC6H3(CN)2, OC6H2(CN)3, OCnH2nOC6H4CN, OCnH2nOC6H3(CN)2, OCnH2nOC6H2(CN)3, OCnH2nOCOC6H4(CN)3, OCnH2nOCOC6H3(CN)2, OCnH2nOCOC6H2(CN)3, OC(OR1)CH2, OC(H)C(H)OR1, ONC(R1)(COR2), ON=C(R1)(R2), ON=C(CN)(C00R2) or ON=HCOR1;    R1, R2, R5 = H or alkyl;    n = greater than 0;    W1 = F, Cl, Br or I;    Y1 = CH2, C5H10C, ArCH, CR3R4, BR3 and BC6H6;    R3 = H, or alkyl;    R4 = alkyl; and    Ar = aryl;