PURPOSE: To obtain the antibiotic useful for agriculture, horticulture and the healths of animals and men by culturing a microorganism in a culture medium containing a specific compound.

CONSTITUTION: This method for producing a macrolide compound comprises inoculating a strain such as Streptomyces thermoarchaensis into a culture medium containing 0.5-10 wt.% of a carbon source such as molasses, 0.1-10 wt.% of a nitrogen source such as urea and inorganic salts such as Na, starting the culture of the strain at a pH of 5.5-7.5 at 25-40°C, adding a water-miscible organic solvent (e.g. an alcohol) solution of a compound of formula I [R' is methyl, ethyl, isopropyl; R2 is H, OR5 (hydroxyl, a 1-25C hydrocarbon group- substituted hydroxyl); R3 is H, etc.], two to four days later, successively aerobically culturing the strain with stirring, extracting the obtained whole fermentation broth, and subsequently purifying the extract, thus producing the 5-OR4 macrolide compound of formula II (R4 is H, methyl) corresponding to the component of formula I.