Variousapproachestothedetermination oftheenergyreleaseratesofcompressively loaded compositelaminates are critically reviewed. These are the J integral, crack-closure integrals, and the direct method, which involves integration of the load-end compression relationship. The J integral is found to be a reliable approximation for the total energy release rate. The use of the crack tip stress e eld for the determination of modal contributions is exploredforcracksbetweenpliesofsameanddiffering materialproperties,respectively.Theassumptionsonwhich this technique is based are critically examined. Finally, a new displacement based method for the computation of modal contributions to G is proposed. This approach is found to be very reliable and provides values of GI and GII with a relatively coarse mesh. This new technique is expected to supplant the currently used stress-based mode separation technique.