Abstract: This invention discloses a method of producing virus-free potato minitubers, which includes the steps of selecting virus-free test-tube plantlets and stem sections cut from seedlings grown 30 days after cuttage of such virus-free test-tube plantlets as cuttaging seedlings, choosing vermiculite as cuttage medium, treating the cuttaging seedlings with plant growth regulators, keeping the growth conditions of the cuttaging seedlings at 25.degree. C. during the daytime and 12.degree.-17.degree. C. at night, relative humidity 95-100% during the early stage and 60-70% at the later stage, and a light duration of ten hours a day with illuminance of 400-600 lux, along with suitable field management of water and fertilizer. The virus-free potato minitubers can be harvested in 30 to 60 days.