A books says that a register is abt 1KB.the books is trustworthy.But aren't they supposed to be 32-64 bits?

http://oi45.tinypic.com/24lpjt3.jpg

Inside the Machine: An Illustrated Introduction to Microprocessors and Computer Architecture

screen capture from the book

32-64 bits each. Altogether 1KB.

The x86_64 family of processors has got 16 general purpose 64 bit registers, making a total of 128 bytes. So 1kb does sound like rather a lot - although I can't claim to be familiar with the architecture of other processor families.

The only processor architecture I know of which has a register file that large is the UltraSPARC, which has (IIRC) 128 64-bit registers (divided into 8 overlapping register windows of 32 registers each).