<p>A tire air pressure detection device of the present invention includes a warning anticipation timing calculating portion for anticipating a warning timing at which tire air pressure decrease detecting portion will detect the tire air pressure decrease based on rotational status value compensated for by a rotational status value compensating portion. A tire air pressure decrease detecting portion detects a decrease in tire air pressure when a determination time reaches the warning anticipation timing anticipated by the warning anticipation timing calculating portion. <IMAGE></p>
