As a purpose of the long term care insurance in Japan, which was inaugurated in 2000, the achievement of "self-support" of aged people was stressed, which means, the prevention of fragility and senility. This system incorporated the new prevention service of "yo-shien" since its beginning. After 5 years experience since 2000, this preventive service was not always found to be effective. Therefore a new procedure of rehabilitation was introduced in 2006, mainly to strengthen the impaired muscle strength to achieve self-support. This new service was evaluated after few years experience and found to be effective in preventing the aggravation of disability and in suppressing the total cost of insurance, compared with control group. To prevent the fragility and senility of aged people, this preventive procedure in the long term care insurance will be effective.