How to increase reputation?Is it relating to the earning or other somethings?

Reputation is earned via the quality of your posts and how you are rated. Especially when you give someone a "best response". Now that you have over 100 posts, you should start seeing a star/number by your user name shortly. In my opinion, the rating is not so important, as it is subjective to the whim of others. You maybe posting great posts, but others may not agree. As long as you are getting the money for your posting, that is all that really matters. That is writing quality posts that are coherent and with correct grammar and spelling. *grins*

The reputation does affect the earnings, though to what extent is unknown being a trade secret of MyLot. http://www.mylot.com/o/faq/faq17.aspx