The laboratory test reveales that the excavated rock materials with high content of palygorskite has potential problems with swelling and dispersion in New Doha port project.Most of the filling materials do not comply with the accepted criteria in specification and shall be considered as unsuitable filling materials.As per specification,the general reclamation fill shall have fine contents of less than 15% with a liquid limit not exceeding 65% and a plasticity index not exceeding 35%.To make full use of these materials and reduce the amount of surplus soil,the EDC has provided new criteria for the unsuitable material based on the structural function on the reclamation surface,i.e.the air void content shall be less than 10% after ground improvement and the volume change shall be less than 1% of the filling thickness.A series of laboratory test comprising particle size distribution test,hydrometer liquid and plastic limits test,swelling test and X-ray diffraction test etc.were scheduled and carried out by local laboratory to verify whether this new criteria has been met for unsuitable filling material.And a correlation has been built between the swelling and fine content. The test result indicated that the unsuitable fill material with fine content less than 45% can be used as general fill material and has been demonstrated by a large scale flooded embankment test.However,the prevention from dispersion should be considered when the filling material with fine content between 20%～45% is used.The research may serve as reference for similar projects in the future.