Cronobacter genus, belonging to the Enterobacteriaceae family, comprises seven species (Joseph et al., 2012a) and ubiquitously exists in environmental sources including water, plants, animals, food ingredients, and a wide variety of processed foods (Iversen & Forsythe, 2003; Friedemann, 2007). Cronobacter spp. will cause opportunistic infection, and most Cronobacter cases were reported in adults (Food and Agriculture Organization and World Health Organization, FAO/WHO, 2008). However, the severe illnesses, such as necrotizing enterocolitis, septicemia, and meningitis that associate with high mortality, mainly occurred in neonates and infants (Himelright et al., 2002). The infections of the newborns were caused by strains from major species of C. sakazakii and other two species of C. malonaticus and C. turicensis (Joseph et al., 2012b). The majority of these illness cases have been epidemiologically linked with powdered infant formula (PIF) (Himelright et al., 2002); however, at least in two independent cases, Cronobacter infections were caused by extrinsic contamination of infant formula so far (Noriega et al., 1990; Ray et al., 2007). Thus, other potential contamination sources are also of concerns, such as unsafe drinking water that was implied by a strain of C. sakazakii isolated from PIF reconstitution water that associated with a Cronobacter case in Illinois in 2011 (Schindler & Metz, 1991; Lee & Kim, 2003; Hariri et al., 2013). Theoretically, drinking water is rarely contaminated in pipes on premises, which makes it the preferred supply way to provide safe drinking water, but in reality, the transferred water may not be as safe as expected, due to inadequately maintained water sources (United Nations International Children's Emergency Fund – UNICEF and WHO, 2012). The piped water supply on premises includes municipal water supply on premises (MWSP) and small community water supply on premises (SCWSP). The definition of SCWSP varies largely within and between countries (WHO, 2012). In the present work, SCWSP was defined as local water supply on premises in township(s) or/and village(s), and MWSP was defined as central water supply on premises in a county town or a city, referring to the Chinese national standard (Ministry of Health and Standardization Administration of the People's Republic of China – MH and SAPRC, 2006). In general, SCWSP systems are no match for MWSP systems in regard to providing stable and safe drinking water (WHO, 2012). In the present study, piped drinking water samples from MWSP and SCWSP were screened for the presence of Cronobacter spp. Because there was no reliable reference method for screening Cronobacter spp. in drinking water samples, a new method should be refined. Membrane filter (MF) method was chosen to be developed, which has been widely used in detection of certain kinds of bacteria, such as coliform, fecal streptococci, enterococci, Staphylococcus aureus, and Pseudomonas aeruginosa etc., and is extremely effective to monitor waters including drinking water and a variety of natural waters (American Public Health Association – APHA et al., 1998; International Organization for Standardization – ISO, 2000). A MF method for detection of Cronobacter spp. in PIF has been designed by Miled et al. (2010) and was compared with a most probable number (MPN) method modified from the ISO/TS 22964 method (ISO and International Dairy Federation – IDF, 2006). Thus, a MF method was adapted from previous MF methods considering its suitability for recovering Cronobacter cells with and without stress results from chlorination in drinking water.