example all parking space sensors 10 may divided into several groups each of which is composed of 10 to 128 parking space sensors 10 each group is then connected to the computer 20 via an individual data bus with reference to fig3 and 4 to improve the management efficiency of the present invention guiding modules 40 are applied on the paths of the parking lot to assist drivers to find an available parking space with reference to fig5 the guiding module 40 includes a direction light 41 a stop light 42 and a vehicle sensor 43 the connection for the vehicle sensors 43 is substantially the same as the foregoing vehicles sensors 10 the vehicle sensors 43 are also divided into several groups and each group is connected to the computer 20 via an individual data bus all the vehicle sensors 43 are able to respond to the moving information of the vehicles to the computer 20 whereby the computer 20 determines a proper path and activates the guiding modules 40 to show the path to the drivers for example if the direction lights 41 are activated to emit green light it means the driver can follow the direction lights 41 to find a proper parking space otherwise if the stop lights 42 are activated to emit red light it means travel along the path is prohibited the vehicle sensors 43 mentioned above are chosen from the ultrasonic sensors or the microwave sensors thus when any vehicle passes through the vehicle sensors 43 the perpendicularly emitted signals are reflected from the bottom of the vehicle so the computer 20 obtains the information of the moving vehicles the invention may be varied in many ways by a.