The invention discloses an intelligent driving assistant system applied to a handheld device. The invention can detect more than one safety mode including lane departure detection, lost-cargo detection, detecting front-object under driving condition, detecting side-object under driving condition and detecting back-object under driving condition, also the invention can mention alarm according to the detection results from different modules. Finally the invention can store the real-time image according to the detection results from different modules, and then transfer the related information to other places for real-time notice with matching the information from the GPS system and the digitized map.