To improve the accuracy of polymer interfacial tension measurement using deformed drop retraction method (DDRM), we examined some factors, such as the shape parameter, the retraction scale Do, and the distortion criterion 7 by means of dissipative particle dynamics (DPD) simulation with 6 different models and analysis with three observation data, and proposing a new shape parameter P. Results show that the shape parameter order of suitable to various retraction scales and larger distortion is P >(a(2)-b(2))> D. This study found that choosing a suitable retraction scale is very important, and that D(0)congruent to 0.15 is the most suitable retraction scale in DDRM measurement. In the scale, the three shape parameters cannot make much difference on the measurement deviation from the standard. This study also found that the distortion criterion gamma varies with different shape parameters. We also found here when D(0)congruent to 0.15 the distortion criterion becomes gamma < 0.15, and one has a reliable measurement with any shape parameter. (c) 2005 Elsevier Ltd. All rights reserved.