Objective To investigate rodent infestation in machinery rooms in a large building complex, to preliminarily explore the spatial distribution of rodents in large building complexes, and to provide a basis for rodent control. Methods In middle and late April, 2018, more than 90 professional technicians performed a general investigation on rodent trace in high-voltage (HV) and low-voltage (LV) machinery rooms and HVAC machinery rooms in a large building complex using the rodent trace method. Excel 2017, SPSS 20.0 and ArcGIS 10.1 softwares were used for data entry, statistical analysis (paired chi-square test), and spatial analysis, respectively. Results A total of 1 304 machinery rooms were investigated, including 532 HV machinery rooms, 377 LV machinery rooms, 386 HVAC machinery rooms, and 9 machinery rooms of other types. The standard positive rate of rodent trace per room were 1.33%, 2.15%, 0.42%, and 0 for the HV machinery rooms, LV machinery rooms, HVAC machinery rooms, and machinery rooms of other types in the venue, respectively, with significant differences observed between the rooms (χ²=14.182, P<0.05); the overall positive rate of rodent trace was 0.85%. The positive rates of rodent trace were 1.69%, 1.26%, and 1.09%, respectively, for the 3rd, 6th, and 1st floors of the building, significantly higher than those on the other floors (χ²=13.051, P<0.05). The positive rate of rodent trace was 1.02% for areas near the main road and 1.09% for areas far from the main road, with no significant difference between them (χ²=0.028, P>0.05). The positive rates of rodent trace for the three areas centered around the central region from near to far were 0.53%, 0.88%, and 1.50%, respectively, showing an increasing trend but no significant differences between them (χ²=3.528, P>0.05). Conclusion Rodent infestation still exists in large building complexes. Rodent activity is closely related to food sources and accessible space. Long-term and continuous rodent density surveillance should be performed and effective control measures should be adopted.