The special medical care in the National Sanatorium prolonged the life span of the patients with progressive muscular dystrophy from 15.8 years to 20.4 years over the last 20 years. Various new drug trials for muscular dystrophy have been implemented in the last 12 years in Japan. Bestatin and Loxistatin, protease inhibitors, showed definite improvement on dystrophic mice or hamsters, animal models of muscular dystrophy. However clinical application of these drugs failed to prove the effects on patients with Duchenne muscular dystrophy. The difficulty of clinical evaluation and judgement of effects in progressive neurological diseases is discussed.