To quantitatively illustrate the ammonia (NH3) emissions from the cement industry in northern China, 14 cement lines were tested with 26 obtained NH3 emission data, and the average NH3 emission concentration was calculated as 35.29 mg/Nm(3). The NH3 emissions of 84.62% of cement lines were above the standard of 8 mg/Nm(3). Factors affecting NH3 emissions were analyzed; the ammonia injection amount in the selective non-catalytic reduction (SNCR) and the operation of raw mills were the main factors, and the NH3 emissions increased as the amount of injected ammonia increased, while it decreased with the running of the raw mill. The average NH3 emission factor (EF) was calculated as 0.07 kg NH3/t clinker, which was higher than the official recommended data, meaning more attention should be paid to NH3 emissions in the cement industry. Effective efforts should be made to prevent more NH3 emissions.