Abstract: This is a study of the reasons for the defeat of the Beiyang Fleet in the Sino-Japanese War of 1894-95 which traces the relationship between military preparation during the years leading up to the war and the ineffective battle formation used by the Chinese in the naval battles on the Yellow Sea.The immediate cause of the Chinese defeat was the complete collapse of the battle formation.But failure was determined by the fact that the fleet’s warship were all outmoded.When they were purchased a decade before the war,the main attacking power of warship was the forward guns(bow chasers)and the ran bow.These ships had few,if any gunwale which were central to the later technology。Reliance on these outmoded ships forced the fleet to use battle formations that moved to be gravely deficient.