Listening in Japanese language

How can I improve my japanese listening skill? I can always hear a word when it is said by itself, but sometimes I don't hear it in a sentence, but there are certain words I will hear no matter the person or accent, like watashi,desu, hai and so on. I watch drama in english sub, but it seems like it is not helping.

In my experience, there are no tricks for improving listening comprehension. For most people, the only option is probably to become immersed,and eventually become accustomed to Japanese spech. Obviously learning grammar and vocabulary is important, but for many people, it can be difficult to comprehend sentences even when people are using words you already know. Watching movies probaly does help, but it may be better to watch them without subtitles. I found that it becames easier to focus on the subtitles rather than the spoken dialogue.

If you want to up your listening, watching without subtitles would be best. That way you will focus more on what a person is actually saying and not focus on the English words at the bottom of the screen.

Also, textbooks with practice CD's are a great tool too. Most JLPT practice books come with CD's so I'm sure if you order one online, that will be helpful as well. You'll have the text in the book to read along with the CD so if you're not sure what they said, everything is outlined for you. If you're JUST starting out with Japanese though even JLPT 5 books may be hard for you to understand but it'll be great practice :)

Of course, the most ideal situation is to find other people who speak Japanese and just listen and try to converse with them. My listening skills got SO MUCH better once I went to Japan since I was surrounded by it everyday. I know this most likely isn't possible for you to do right now but if you can do it one day you will see how easy listening becomes after a short time.

The bilingual subs are just terrible. Many times lost in translation. Often they switch who is the subject. Often paraphrased by the translater. Some are translated by foreigners who don't understand/know Japanese well. It seems nobody is checking.
My suggestion is to not rely on the subs butlisten many times or get proper materials.

I am not a good Japanese speaker. However we found that listening to children talking Japanese was very helpful. They don't seem to have the slang and inflections that adults do.