一、前言本世纪以来,国外对儿童少年生长发育长期加速的现象(指一代儿童在一定时期内的发育速度与另一时期的一代儿童在发育上有显著的差异,称为长期加速)已早有报导。我国有的城市进行了几次大的调查与比较也证明了这种发育上的长期加速事实。但近期发现总的趋势是随年龄的增加而发育减慢的变化特点,还未见有关问题报告。已知这种发育上的“长期加速”现象,並不是始终保持加速地发育,而是到了一定时期, I. Foreword Since the beginning of this century, the phenomenon of long-term growth of children and adolescents in foreign countries has been accelerating since the beginning of this century (referring to the significant difference in development between children in a certain period of development and that of children in another generation, referred to as long-term acceleration) There are reports. In some cities in our country, several major investigations and comparisons have also proved the long-term acceleration of this development. However, it has recently been found that the general trend is that it changes slowly with the increase of age, and no report on the problem has been found yet. It is known that this phenomenon of “long-term acceleration” in development is not always maintained at an accelerated pace but has reached a certain period of time,