JPCt are a groups of classes, so you just need to import the using import bla bla bla, BUT those clases are defined in packages too, thy need to be put on the classpath. for example your jpct classes are in "c:\jpct", and you are coding a programm in C:\myprojects\NB, then it wont work, you must have the joct classes and you project at the same level of directories.