Where can I find dataset for word analogy task? In the paper of Word2Vec by Thomas Mikolov and others, there is a accuracy report on the full Semantic-Syntactic data set. Where I can find this dataset or a related dataset for word analogy task? 

Here is the paper link and I'm referring to table 5. 
https://arxiv.org/abs/1301.3781
If i understand correctly you want a long text file of some sort that can easily be analysed. I would suggest that you use project Gutenberg which publishes thousands of free to use books in plain UTF-8 text format. For example here is Pride and Prejudice by Jane Austin.