The ASM1 model is accepted as a reference to predict and understand the processes of organic matter degradation, nitrification and denitrification in systems activated sludge. To calibrate the model, requires estimate kinetic parameters such as the maximum grow rate (μ_HMAX) and decay (b_H) heterotrophic. These parameters have been studied for temperatures under 20°C. The objective of this investigation was to evaluate μ_HMAX and b_H in a range of temperature of 20 at 32°C in the wastewater treatment plant "Dulces Nombres" in Monterrey, Nuevo León, México. The work was based on respirometric tests as part of the calibration of the model ASM1. The fraction of substrate readily biodegradable (S_S) was low (34 mg/L) difficult tests for growth. For evaluate μ_HMAX was necessary to add sodium acetate to obtain a durable growth of the microorganisms and thus to estimate this parameter. The tests of respirometry, were made at temperatures of 20, 24, 28 and 32°C. The results average of μ_HMAX and b_H for 20°C were 6.9 and 0.40 d^-1 respectively. The correction factor by temperature change (θ) of Arrhenius for μ_HMAX and b_H was 1,045 and 1.04 respectively, which can be applied to conditions of warm climate or tropical.