Pipes of Zr-Sn-Nb-Fe alloy with the extruding temperature of 600, 620 and 640 oC were prepared by 600 oC extruding, first rolling and second rolling. The microstructure of the alloy was observed by SEM and the evolution of secondary particles and their size statistics were studied. Results show that all the second phases are distributed dispersively under different extruding conditions. The size of secondary particles is increased at higher extruding temperature. During the process of extruding and rolling, the size of the second phase decreases with the increase of processing degree, and the shape of the second phase changes from irregular to globular