ABSTRACTe-Main-Seque
         A 
          relatively new and rather unexplored class of variable stars is represented 
          by the PMS $\delta$ Scuti stars. The number of
          these pulsators has rapidly increased during the last few years, also 
          thanks to our theoretical and observational efforts.
          I will briefly review the status of the art for these objects, and present 
          recent results obtained by our group.
          The comparison between theory and observations is used to derive information 
          on the distance and intrinsic stellar parameters.
          Future developements are briefly discussed.