referring now to fig1 , 3 and 4 , the skateboard of the present invention is provided with rollers 11 from beneath for skating , one hole 12 at least formed within the area on the board available for stepping on and an electronic box 3 affixed from beneath with screws 4 . the body of the electronic box 3 comprises the upper shell 32 , the lower shell 33 and the circuit board 34 . a flange 321 is formed on the top of the upper shell 32 with a size which fits properly in the hole 12 of the skateboard and a height equals generally to the thickness of the skateboard , preferably around 5 mm - 25 mm ; the flange 321 has further a central hole 322 which is narrowed at the middle of the height to form a shoulder 323 . on the circuit board 34 , a touch - off means 341 comprising a spring element 342 is provided right beneath the hole 322 of the flange 321 , and a hand - operating second switch means 343 is also provided thereon stretching out of the electronic box from the side . referring now to the lower shell 33 of the box , there is provided a battery chamber 331 receiving the battery to supply electricity to the device as well as a speaker 332 . furthermore , the pedal 2 of the touch - off means 341 is formed at its top an enlarged flat surface 24 with a post 21 thereunder and at its lower end an enlarged conical end 22 for sticking easely into the shoulder 323 of the flange hole 322 whereby the conical end will be held by the bottom edge of the shoulder 323 in the hole 322 to keep the pedal 2 from coming off the box 3 . the post 21 of the pedal is available to move up and down freely in the hole 322 , however , it is kept constantly at its upmost position by the spring element 342 . the circuit board 34 is firstly mounted into the upper shell 32 by screws 5 and then this combined set is mounted onto the lower shell 33 by screws 6 driving into the studs 333 and 325 in the lower shell . as the flat surface 24 of the pedal is stepped to descend , the conical end 22 at the lower end of the post 21 will descend along with the post and press the spring element 342 to set on the touch - off means 341 and electrify the ic on the circuit board , whereby the speaker 332 in the lower shell is sounding or the bulbs 334 disposed on the surface or the side of the skateboard are lighting consequently to achieve the sound and light effect for the skateboard ; when the stepping pressure is removed , the spring element 342 will return to its original position and cut off the circuit as getting ready for next touch . to assure the pedal to be forced downwards smoothly without unefficient rotation , a u - shaped slot 231 , as shown in fig5 is formed at the base 23 of the flat surface of the pedal for a convex strip 3221 , formed at the upper part in the flange hole , to fit in so that the pedal will not be able to rotate . as the stepping pressure is brought to the pedal , the conical end 22 will accordingly be forced downwards directly and touch off the electricity smoothly . moreover , variety of the circuitry can be made in the present invention to bring in various functions , e . g . touch - off phonic system , music ic or light glittering control circuit ; more pedals can be added to the device as needed ; and the hand - operating 2nd switch means 343 on the circuit board of the present invention can be formed as a multi - selection switch available for selecting different effects according to different preference .