Article in English: The flowers are typically pollinated by insects, or pollinate themselves in some varieties, so there is no need to pollinate by hand unless you are breeding specific plants together. Leave the flowers on the rose plant without cutting them. After they wither, small fruits known as rose hips will develop in their place.  Note: The seeds you harvest may grow into a plant with different characteristics. This can occur if you are harvesting from a hybrid rose variety, or if the rose is pollinated with pollen from a different, nearby rose variety. The rose hips will start out small and green, then change color as they grow until they are completely red, orange, brown, or purple. You may pick them at this point, or wait until they are just beginning to dry out and wrinkle. Don't wait until they are fully dry and brown, as the seeds inside may have died by this point. Cut open the rose hips with a knife, revealing the seeds inside. Pull these out with the knife tip or any other utensil. The number of seeds in each rose hip varies greatly between rose varieties. There may only be a few per rose hip, or several dozen. If the pulp is left on the seeds, it may prevent them from germinating. One quick way to remove the pulp is to place the seeds in a sieve or mesh, running water through it as you rub the seeds against the sides.

Summary in Chinese:
等待玫瑰花凋谢后结成玫瑰果。 摘取成熟的玫瑰果。 切开玫瑰果，取出种子。 洗去种子表面的果浆。