This study examined mother-child book reading of immigrant, low-income Latino families in family literacy programs. A total of 92 Latino children (4 to 5 years old) and their mothers were observed reading a book together. The affective quality of mother-child behaviors and the type of maternal talk occurred during book reading were coded. During book reading, mothers showed high levels of warm/positive behavior and low levels of intrusive/negative behavior. In addition, mothers spent most time reading the text in the book, discussing the immediate book content the next, and discussing the non-immediate book content the least. Variations in book reading were observed as a function of child's age, child's engagement in book reading, and child's language use. Moreover, maternal use of family literacy service, especially parent-child joint literacy activities (PCILA) was differently associated with book reading. Regression analyses found that child's language mix predicted the affective quality of book reading in warm/supportive behavior and the extent of maternal talk on reading the text and discussing the book content. PCILA was a positive predictor of the extent of maternal talk on discussing the book content. Child's engagement in book reading was positively related to the affective quality of book reading in warm/supportive behavior and the extent of maternal talk on discussing the book content. These findings have implications for early intervention programs which provide book reading training for bilingual families. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]