"1. is it need to write all interupt loops before start(intializing) loop in asm programming and iam asm51 compiler,
have nice day "

How can I, after you ask such a question ?!

It does not matter when you write the Interrupt Service Routines (ISR) as long as you write it before going to bed. By which I mean before you complete your full asm code.

The location of the ISR in your code is a non-issue. It is a set of code that is complete by itself ( ends with a RETI ) and thus can be anywhere. But enabling the particular interrupt source for the ISR is a major issue and depends on the requirement. Good coding parctice is to intialize all relevant SFRs at the very begining of the main code.

If you have any further doubt read the Tutorials on the left.

Raghu