In this study, the elevated temperature deformation behavior of AA6063 alloy has been investigated within the temperature range 625-725 K at constant compression-head speeds, 0.5, 2, 5, 10 and 20 cm/min of test machine respectively. To evaluate the flow stress of AA6063 alloy in hot working processes, a formula is derived by analyzing the stress-strain curves obtained from tests at various temperatures and head speeds. The stress-strain curves were divided in to two ranges as work hardening part and flow softening part, limited pick strain, epsilon(p). Since all the curves showed different hardening and softening exponents, used in sigma = sigma(p)(epsilon/epsilon(p))(n) formula, sigma(p) and n exponent have expressed depending on Zener-Hollomon parameter and test temperature respectively. It is demonstrated that a linear equation of the logarithmic Z fits the flow stress of the alloys at elevated temperatures. Obtained model curves were compared with experimental curves and as a result, work hardening and flow softening parts in equations were generally in a good agreement with experimental counterparts. (C) 2013 Elsevier Ltd. All rights reserved.