Reactivity ratios for hydroxy．containing monomers such as 2-hydroxyethyl me-thacrylate (HEMA) and 3--methoxy．2-hydroxypropyl methacrylate (MHPMA) with acrylonitrile (AN) or acrylamide (AAM) systems have been determined for radical co-polymerization at 60℃ in different solvents．The reactivity ratios computed by Kelen-Tudos and the Fineman-Ross and intersection graphitic methods have been compared．The values of r1=0.22—0.25，r2=0.97—1.05 for AN (M1)．HEMA(M2)，in DMSO or DMF initiated either by azobisisobutyronitrile (AIBN) or by potassium persufate (KPS)-iso-propyl alcohol (IPA)，the reaction media and initiator would not play a pronounced ef-fect．While，in AAM-MHPMA or AAM-HEMA，the values of reactivity ratios are as follows：r1=0.0433，r2=3.98 for the former case。and r1=0.0535，r2=1.89 for the later case，respectively．These distinet different values between r1 and r2 showed that the AAM monomer is more difficultly enter to the eopolymer composition than the AN monomer．