Abstract: The operation cost for measure well was increasing and the measure efficiency was declining since Laojunmiao oilfield entered into the later period of development. This paper presented the characteristics of well stimulation in M reservoir of this oilfield during 2008-2012, developed the input-output efficiency evaluation model for the measured wells using data envelope analysis (DEA), and conducted a case study. Research shows that when sampling unit is effective unit, the generalized DEA model is the same as the traditional DEA model in the result; when sampling unit is not a decision making unit, the results from these two models are different. Also, it is suggested that during the period of 2008-2012, the input-output efficiency of the measures available tended to decline, in which the average efficiency of sand control was higher than those of other measures, and the efficiency of sidetrack overhaul was lower than the others’