i want to interface sensirion with 89c51

"can any one guide me about how to interface sensirion Sensor SHT10 with 89c51."

Last time I downloaded sample code from Sensirion, which admittedly was a few years ago, it was written for an 8051 derivative using Keil tools.

"any site that will help me in this respect."

In case it's not obvious, http://www.sensirion.com/ .

"can any one guide me about how to interface sensirion Sensor SHT10 with 89c51."

Last time I downloaded sample code from Sensirion, which admittedly was a few years ago, it was written for an 8051 derivative using Keil tools.

"any site that will help me in this respect."

In case it's not obvious, http://www.sensirion.com/ .

In other words, you need to learn assembler first - the specifics of the Sensirion sensor will come later.

Try the booklist here:
http://www.keil.com/books/8051books.asp

Or here:
http://www.8052.com/book

There are also tutorials here:
http://www.8052.com/tutorial.phtml

And don't forget those documents commonly referred to as the "bible" for the 8051:

Chapter 1 - 80C51 Family Architecture:
http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_ARCH_1.pdf

Chapter 2 - 80C51 Family Programmer's Guide and Instruction Set:
http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_PROG_GUIDE_1.pdf

Chapter 3 - 80C51 Family Hardware Description:
http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_HARDWARE_1.pdf

Your Keil installation includes an 'Examples' folder with a simple assembler sample program.

See: http://www.keil.com/forum/docs/thread7041.asp

That would be a good place to start.