To observe the seasonal and diurnal variations of atmospheric carbonyl, thirty six carbonyls samples were collected and fourteen carbonyl compounds were identified in Foshan City during winter 2014 and summer 2015. Most carbonyls were observed with high average concentrations in Foshan City and the total concentrations of carbonyls were 36.15μg/m³± 3.45μg/m³ and 33.25μg/m³±4.25μg/m³ in winter and summer, respectively. Formaldehyde (8.54μg/m³, 23.65%), acetone (8.20μg/m³, 22.69%), acetaldehyde (5.79μg/m³, 16.03%) and formaldehyde (14.63μg/m³, 44.01%), acetaldehyde (6.22μg/m³, 18.70%), acetone (5.23μg/m³, 15.73%) were the three most abundant carbonyls in winter and summer, respectively. The diurnal variations of carbonyls remain at a relatively stable and high level in winter, and carbonyls in afternoon were slightly higher than those in the morning and evening. On the contrary, it varied significantly in summer and the carbonyls in afternoon were significantly higher than those in the morning and evening. The ratios of C1/C2 and C2/C3 were 1.56 and 14.35 in winter, and 2.63 and 15.56 in summer, respectively. Human activities were the main sources of carbonyls in Foshan City. The good relationship among formaldehyde, acetaldehyde, acetone and propionaldehyde indicated those carbonyls might have similar sources.