In an apparatus for detecting condition of load connected to a general-purpose internal combustion engine, a first threshold value is compared with a sum obtained by adding a predetermined value to a detected throttle opening and changes the threshold value to the sum if the first threshold value is less than the sum and the engine is determined to be under first load condition if the throttle opening exceeds the threshold value. Next a second threshold value is compared with a difference obtained by subtracting change amounts of the engine speed and throttle opening and the engine is determined to be under second load condition if the difference exceeds the second threshold value, thereby enabling to accurately detect a condition of a load connected to the engine. Then the desired engine speed is changed in response to results of the determinations.