Abstract: Measurement uncertainty was evaluated for temperature stability of effective incubation area in incubators．According to JB/T 9809.2—2013, temperature of effective incubation area in incubators was measured and a measurement model was established．According to JJF 1059.1—2012, sources and influencing factors of uncertainty were analyzed, and uncertainty of measurement results was evaluated．Results indicated that expanded uncertainty of temperature stability in effective area of incubator incubation was U=0.18 °C, and uncertainty component introduced by instrument calibration was main factor affecting uncertainty of measurement results for temperature stability in effective area of incubator incubation．