To study the emission characteristics of carbonyl compounds for in-use diesel vehicles on real roads, nine in-use heavy-duty diesel trucks (HDDTs) representing different emission standards from China 0 to China 3 were tested on roads in Xiamen using an on-board carbonyl compound sampling system with a 2,4-DNPH cartridge. High-performance liquid chromatography (HPLC) was used to quantify the carbonyl compound emission factors. In total, 10 carbonyl compounds were detected for all the tested vehicles in this work. Formaldehyde, acetaldehyde and propanal were the three largest contributors of carbonyl emissions, accounting for 47.9%, 21.0% and 9.9% of the total carbonyls, respectively. The emission standards had a significant effect on the emission factors and profiles of the carbonyl compounds from the test vehicles. The total emissions of carbonyls from the test vehicles with China 0, China 1, China 2 and China 3 emission standards were 318.4, 232.8, 108.1 and 88.8 mg/km, respectively. The relative contribution of formaldehyde to the total carbonyl emissions increased with increasing stringency of the emission standards. Driving patterns also affected the vehicular carbonyl emissions. The total carbonyl emissions under highway driving cycles were lower than those under non-highway driving cycles. In addition, the ozone-formation potential of the carbonyls from the tested diesel vehicles was analyzed. This work represents a preliminary step in measuring carbonyl emission characteristics using portable emission measurement systems (PEMS). More attention should be paid to carbonyl emissions from HDDTs.