In th is stu d y , T h e a lte ra tio n o f th e d ia m e te r d is trib u tio n by site q u a lity an d age, p re se n te d by th e a ctu ai s tru c tu re o f ev an ag ed o rien ta! beech sta n d s in th e W est B lack Sea reg io n o f T u rk ey , has been re la te d to th e m odels constru c te d by b asin g on th e m odels has been o b tain ed fro n ı 116 te m p o ra ry plots. A Iin ear m odel h as been c o n stru cted for each d istrib u tio n , and th e coefficients in th e m odel h ave been co ın p u ted w ith the heip o f reg ressio n analysis. Besides, s ta n d a r t e r r o r an d m u ltip le c o rre la tio n co efficien ts h av e also been d e te rm ined. L a te r, th e estim ad e values th at th e d e te rın in e d m odels gave have been g rap lıically c o m p a red vvith th e actu ai m easu rem en ts. G a m m a m odel seem s to be m ore su itab le th a n th e o tlıer d istrib u tio n m odels.