Your website trafffic could be decreasing for a variety of reasons.
I'd like to be able to answer your question, but there's a lot of questions here that I would need answered - 1. What's your website? 2. When did you see this change occur? 3. Did you make any changes to your website in the past day or two (before the decrease)?
how i want to know that why my website traffic is decreasing? If any body know then help me
My website is related with website development.
i did check traffic by analytic from aug. to sep.
traffic is decreasing in sep.
yes we had some changes bt that are according to the google.
I'm going to second woodroseint's comment and yes it could have been the position of the actual keywords. Without seeing your website, it will be difficult to determine how well your site is optimized. One interesting tidbit I did find was that Google's latest algorithm update was the Hummingbird update, which may have effected your page ranking. However, if I'm going to guess anything it's the new changes you made to your website. I would recommend taking a look at the Beginner's Guide to SEO by MOZ: http://moz.com/beginners-guide-to-seo - each time I read this, I find new things :)
Your website traffic may be decreasing becasue your site is now not ranking on top page of search engine. Check ranking of your website and if it is not ranking then do on page and off page optimization on website.