A method for production of recombinant human FSH comprising the steps of: (a) culturing recombinant human FSH-producing mammalian cells in a serum-free medium to let them secrete recombinant human FSH in the medium, (b) collecting culture supernatant by removing the cells from the culture that is obtained in step (a) above, (c) subjecting the culture supernatant collected in step (b) above to cation-exchange column chromatography to collect recombinant human FSH-active fractions, wherein the cation exchanger employed in the cation-exchange column chromatography is a weak cation exchanger having a selectivity based on both hydrophobic interaction and hydrogen bond formation, wherein the recombinant human FSH is let bind to the cation-exchange column that has been equilibrated with a phosphate buffer of pH 5.0-6.0 supplemented with 50-250 mM of sodium chloride, and wherein the recombinant human FSH is eluted from the column with a phosphate buffer of pH 5.5-6.5 with an increased concentration of sodium chloride at 400-800 mM, (d) subjecting the fractions collected in step (c) above to dye affinity column chromatography to collect recombinant human FSH-active fractions, wherein the dye employed in the dye affinity column chromatography is a blue triazine dye, wherein the fractions collected in step (c) are adjusted in advance to pH 7.8-8.2, with a buffer, and are applied to the dye affinity column that has been equilibrated at pH 7.8-8.2 with a buffer, and wherein the recombinant human FSH is eluted from the column by increasing the concentration of potassium chloride to 1.8-2.2 mol/L, (e) subjecting the fractions collected in step (d) above to hydrophobic column chromatography to collect recombinant human FSH-active fractions, and (f) subjecting the fractions collected in step (e) to gel filtration column chromatography to collect recombinant human FSH-active fractions. (a) culturing recombinant human FSH-producing mammalian cells in a serum-free medium to let them secrete recombinant human FSH in the medium, (b) collecting culture supernatant by removing the cells from the culture that is obtained in step (a) above, (c) subjecting the culture supernatant collected in step (b) above to cation-exchange column chromatography to collect recombinant human FSH-active fractions, wherein the cation exchanger employed in the cation-exchange column chromatography is a weak cation exchanger having a selectivity based on both hydrophobic interaction and hydrogen bond formation, wherein the recombinant human FSH is let bind to the cation-exchange column that has been equilibrated with a phosphate buffer of pH 5.0-6.0 supplemented with 50-250 mM of sodium chloride, and wherein the recombinant human FSH is eluted from the column with a phosphate buffer of pH 5.5-6.5 with an increased concentration of sodium chloride at 400-800 mM, (d) subjecting the fractions collected in step (c) above to dye affinity column chromatography to collect recombinant human FSH-active fractions, wherein the dye employed in the dye affinity column chromatography is a blue triazine dye, wherein the fractions collected in step (c) are adjusted in advance to pH 7.8-8.2, with a buffer, and are applied to the dye affinity column that has been equilibrated at pH 7.8-8.2 with a buffer, and wherein the recombinant human FSH is eluted from the column by increasing the concentration of potassium chloride to 1.8-2.2 mol/L, (e) subjecting the fractions collected in step (d) above to hydrophobic column chromatography to collect recombinant human FSH-active fractions, and (f) subjecting the fractions collected in step (e) to gel filtration column chromatography to collect recombinant human FSH-active fractions.