Step 1: Understand the context of 周文王 (Zhou Wen Wang)
周文王, also known as King Wen of Zhou, was a king of the Zhou Dynasty in ancient China、He is known for his wise and just rule, and is considered one of the most important figures in Chinese history.

Step 2: Identify the writings associated with 周文王
周文王 is associated with the authorship or compilation of several ancient Chinese texts, most notably the 易经 (I Ching or Book of Changes).

Step 3: Clarify the specific writing attributed to 周文王
The 易经 is an ancient divination text and one of the oldest Chinese classics、While 周文王 is credited with significant contributions to its development, specifically the 周易 part, which involves the interpretation and expansion of the original 易 text.

Step 4: Determine the nature of 周文王's contribution to the 易经
周文王's contribution is believed to be the addition of the 卦辞 (卦辞 refers to the explanations or judgments associated with each hexagram), which are considered crucial for understanding the divinatory and philosophical aspects of the 易经.

Step 5: Consider other possible writings or contributions
Besides the 易经, 周文王 is also associated with other literary and philosophical works, but the 易经 remains his most famous and enduring contribution.

The final answer is: $\boxed{易经}$