Breastfeeding has many health and developmental advantages for infants and mothers and is the preferred way of feeding infants to promote optimal infant health and reduced morbidity later in life [1–3]. In Asian cultures, and perhaps more generally, breastfeeding also protects against early Helicobacter pylori infection [4–7]. A recent cohort study from Shanghai suggests that breastfeeding may offer a mother some protection against developing Type II diabetes . Breastfeeding has received increased emphasis in China over the past two decades as its importance for child health has become recognized. In order to implement the spirit of the World Summit for Children, the Chinese government issued the "National Programme of Action for Child Development in China in the 1990s" 
A number of cross-sectional and longitudinal studies in China showed that the 'ever breastfed' rate, both in urban and rural areas was over 80% in the 1950s and 1960s. During the 1970s and 80s the use of breast milk substitutes became more popular and the national 'ever breastfed' rate decreased, gradually dropping from about 80% in the 1960s to 42.7% in 1975 and it then fell further to 33.6% in 1985 . The trend was even more marked in the large cities such as Shanghai, where the rate fell to 22.2% in 1982 and again to 13% in 1989 [10, 11].
The International Baby Friendly Hospital Initiative was introduced with the goal of ensuring that all infants are breastfeeding before their discharge from the hospital and that 80% would be exclusively breastfed for the first six months of life . By 1994, in China a total of 947 hospitals had passed the National Baby Friendly Hospital assessment  and since that time the number of BFHI certified hospitals has continued to increase. During the 1990s the Chinese government introduced women and child health protection legislation, society support programs and education programs to support breastfeeding promotion.
Following the introduction of these programs the breastfeeding initiation rate began to rise again. A survey in one of the largest cities of western China, Chengdu, Sichuan province showed that the 'ever breastfed' rate had risen to 88% in 1993 . A longitudinal study found that the 'full breastfeeding rate' was 78% at six weeks in the east coast city of Zibo, Shandong province in 1996 . A survey of mothers from 105 counties showed that by 1995 the breastfeeding initiation rate was well over 90%, but the exclusive breastfeeding rate was low . In a cohort study from the west of China the any breastfeeding rate on discharge was 92% and 73% were continuing to breastfeed at six months . While the trend in breastfeeding rates is encouraging, many of these studies were cross-sectional surveys and have inherent limitations in the information provided on risk factors that could be used in health promotion programs.
Factors that are important in the initiation of breastfeeding include a favourable paternal attitude toward breastfeeding, as perceived by the mother , whether the mother had an operative delivery, giving prelacteal feeds and ethnicity . The time that the decision to breastfeed is made, maternal age and education and smoking patterns are also important in some societies [20, 21].
Zhejiang province is located in the mid-east coast region of China and has benefited from economic reforms and for the past three decades has had one of the fastest growing regional economies in the country. The economic improvement has created many new job opportunities for the younger generation in high technology industries and has resulted in a large, well educated middle class in the provincial capital of Hangzhou. The rural areas have not benefited as much from the rapid development and people from rural Zhejiang and other provinces continue to move to the capital city and suburban areas in search of a more prosperous city life. In 2006 the provincial population was 49 million with one of the highest population densities in the country. Hangzhou has a population of six million and advertises itself as the "most beautiful city in China" and the many emperors and government officials who have holidayed there in the past bear testament to this fact.
Like other big cities in China, the breastfeeding experience of Zhejiang women has changed over time. A cross-sectional survey undertaken in five cities in Zhejiang in 1997 found that the exclusive breastfeeding rate before discharge was 74.4% and this dropped to 43.7% at 10 weeks . This rate was lower than the World Health Organization target for initiation and for exclusive breastfeeding for six months. In China at the present time the initiation rates of breastfeeding are high and the most important issue is the rate of exclusive breastfeeding . A recent review and study of breastfeeding in rural China confirmed the low rate of exclusive breastfeeding and concluded "health care providers need to intensify education and counseling concerning breastfeeding and especially emphasize the importance of exclusive breastfeeding from birth to 4 to 6 months of age"  (p.384). A literature search of the English and Chinese language medical literature failed to find any previous longitudinal studies of breastfeeding in Zhejiang Province prior to this cohort study. The differences in breastfeeding rates in rural, suburban and city areas and the first feeds given in Hangzhou, have previously been described [25, 26]. This analysis explores the factors that are important in the initiation of exclusive breastfeeding in Zhejiang Province, PR China.