One scheme of integrated navigation Kalman filter positioning algorithm was put forward to apply to “Beidou” and INS（intertial navigation system）.Using the pseudo-range’s velocity of changing as observations

on the basis of the high stable clock

a closed loop Kalman filtering model that can revise the attitude error of INS was put out

its biggest optimism was that it could change between the close-loop method and open-loop method steadily.Finally

by computer simulation

it explain that our scheme improve the positioning precision effectively when the satellites in sight are less then two ones

and it also show that our scheme can revise the attitude error of INS effectively and estimate the user’s velocity in high precision.