The detection of genetic variability in natural or man-made populations/ plantations is useful in both basic and applied biology. In addition to the various facets of studies on 
Shorea  javanica  already  initiated  by  Torquebiau  (1984)  and  alongside  with  his recommendations  on  focus  for  future  research,  a  study  on  the  genetic  aspects  of  the 
species should be given  important  considerations. As  the  trees are  tapped  for  resin, an important  forest  product,  the  genetic  basis  of  the  production  as well  as  the  range  of 
variation in amount of resin production among  the trees must be known. Coupled with this is a thorough investigation on the differences in pest resistance/susceptability among the  trees and  their genetic basis. While  the assumption  (Torquebiau 1984)  that  trees  in natural  forest  areas  are-rarely  attacked  by  diseases  because  of  mycorrhizal  fungi  is 
interesting, its confirmation is necessary. If this is true, problems would arise when plants are introduced into a new plantation site as experienced by the Forest Research Institute 
(Ardikoesuma 1954). Thus, we need  to  look  for pest  resistant plants  i.e.  those  that can remain healthy even in the absence of mycorrhizae. The  above  studies  on  possible genetic  variation  could  give  vital  information  for 
development of forest plantations of the species and for breeding and tree improvement strategies.  By  knowing  the  extent  of  genetic  variation  in  natural  population  or  in 
plantations one could be guided to maintain or increase the genetic base in these areas. Biochemical characters such as isozyme banding patterns have been useful in several 
areas  of  plant  biology,  population  genetics,  evolution  and  breeding.  Isozymes  are detected by starch gel electrophoresis and when their genetic control  is established, they 
could  be  genetic  markers  in  analyzing  variation  in  morphological  or  physiological characters. The  present  study  is  an  attempt  to  detect  the  isozymes  in  leaves,  seeds  and cotyledons of Shorea javanica by gel electrophoresis.