Abstract: Bis-(p-toluene solfonale)of 2,4-hexadiyne-1,6-diol(TS)monomer is a macroscopic single crystal which can polymerize into polymer single crystal(PTS)without changing its crystal mode under heating.The macroscopic dimensions of TScrystal during solid state polymerization have been monitored by means of laser micrometry.The change of parameters of unit cell during polymerizing TSinto PTScan be estimated from the measuring of the dimensions of the single crystal.The results show that c axis of unit cell which is the direction of forming PTSmacromolecular chain contracts during whole polymerization,but both a and b expand firstly,then contract.