Bird nest-site selection is an important topic in avian ecology, especially with respect to bird reproduction success. In the past decades, urban avian ecology has attracted more attention, because determination of how birds adapt to urban areas could improve the ecological functioning of urban ecosystems and help to build a better living environment for both the human being and urban wildlife. Sand martin (Riparia riparia Linnaeus 1758), a bird species belonging to Passeriformes, Hirundinidae, Riparia, is distributed throughout the world except for Australia. In recent years, sand martins have become an urban bird that can reproduce in Zhengzhou City, Henan Province, the People's Republic of China. The sand martin predates Diptera, mosquitoes, and other insects, and therefore plays an important role in eliminating insect pests from urban environments and maintaining ecological stability in cities. However, in the Zhengzhou suburb, there is a conflict between human urbanization and sand martin nest-site selection. Sand martin nest-sites are mainly located on vertical sections of cliffs, which are formed by new mining tunnels or by the hillock formed after bulldozers backfill the tunnel base. To alleviate the conflict and promote eco-city construction, it is necessary to understand the habitat characteristics of the sand martin and the dominant factors affecting its nest-site selection. A survey was conducted to study the nest-site selection of four sand martins in the suburb of Zhengzhou, using a plot method based on field observations from March to August 2014. For either burrow nests or control areas, a total of 160 data sets were collected, and Mann-Whitney U test was adopted to analyze the data. The main ecological factors affecting sand martin nest-site selection were determined by stepwise discriminate analysis, and the Standardized Canonical Discriminant Function was formed. The results showed that 1) the nest hole diameter was (8.46±0.79) cm, longitudinal diameter was (8.30±0.79) cm, depth was (87.80±11.97) cm, nest chamber diameter was (11.25±1.33) cm, longitudinal diameter was (10.43±1.33) cm, and height was (9.99±1.33) cm. 2) There were significant differences in vegetation height, vegetation density, slope position, slope, cliff height, cliff length, cliff age, and degree of disturbance between nests and control areas. Sand martins preferred higher vegetation (97.24±8.42) cm, greater vegetation density (64.34±7.15) plant/m², steeper slopes (83.78±0.35) °, higher slope positions (1.41±0.04), greater cliffs (7.54±0.13) m, longer cliffs (51.18±3.54) m, smaller cliffs age (2.41±0.05) month, and a lower degree of disturbance (1.94±0.06) of the habitat surrounding the nests than the control areas. 3) The results of the stepwise discriminate analysis showed that the main factors affecting sand martin nest-site selection were slope position, cliff age, and degree of disturbance. The Standardized Canonical Discriminant Function was y=0.753×slope position+0.681×cliff age+0.288×degree of disturbance. Based on our findings, we offer several suggestions for protecting the sand martin according to the characteristics of its nest-site selection during urbanization.