Asked in Chronicles of Narnia
Is The Chronicles of Narnia a Christian Fiction book?
No. Although it is noteworthy to mention that CS Lewis was a Christian at the time that he authored those stories and there is much inference to Christian truths throughout them.
While the books do indeed espouse many of the Christian ethics it is important to note that ethics are not original to the Christian faith. Lewis addresses this point in many of his works but especially in "The Abolition of Man".
I will add however, that while I believe that "Jack" himself probably would deny that the "Chronicles" are a Christian story that he would probably do so with tongue in cheek.