How i will connect an LCD 16*2 on arduino uno?
All you have to do is use a whole lot of hot glue and slap the LCD unit straight on to the top of your Arduino. In this schema, orientation isn't important, but it will probably look best if you keep the long edges of each board parallel. Don't worry about soldering header pins onto anything or learning to program-it will only be a further waste of your time. Make sure to fill any holes in the side of the Arduino with hot glue too-especially the ones in the little silver and black boxes. You see, LCD stands for Liquid Crystal Display, and the last thing you want is for any of that liquid to leak out of the microcontroller, especially from the USB or power inputs. Hot glue makes an effective seal, and its use will appease Hoff70, Kariloy and maybe FritsL. Once you've done that, just zip-tie it to a car battery for power and put your forehead next to the whole assembly and think really hard about what you want it to do. The sketch will upload via telepathy. Be careful to avoid LiPo car batteries-much like the recently grounded 787 "Dreamliner" they have been problematic with the Arduino systems. In particular, some Mega 2560s and DUEs have attained sentience and run amuck. Luckily, in all reported cases, the only actuators attached were fairly weak 9g servos and the family pet usually put the abomination to rest.
Or you could do your homework. Out of curiosity, why wouldn't one go to a search engine for this information first? The Internet is about instant gratification. It seems counterintuitive to post a query in a forum and have to wait for what will inevitably be a link that someone else picked off of a search engine.
I would assume, if you can not do a simple task such as googling "16x2 LCD Arduino", then actually hooking up the LCD itself is probably too much for you.
I am sorry to be harsh, but for cryin' out loud. "Arduino LCD" has got to be one of the most simple, straight-forward, always-brings-up-what-you-need, searches there could possibly be.
Effort. (Need some)
I have to agree with Chris. You were asking questions in the shout box with a similar level of detail as this post, it is not helpful at all to us to try to answer and a google search gave all the information that you needed. Again like Chris said we aren't being hard on you its just a little annoying when people don't try to solve problems themselves.