An LED light bulb, comprising: a bulb shell; a bulb base connected to the bulb shell; a stem disposed inside the bulb shell; at least two conductive supports (51a,51b) connected to the stem; an LED filament comprising a plurality of LED chips (102,104) and two conductive electrodes; and a plurality of supporting arms, each of the supporting arms comprising a first end connected to the stem and a second end connected to the LED filament; characterized in that each surface of the LED chips are covered by a top layer and a base layer, the top layer comprises an adhesive and a plurality of phosphors, the base layer comprises an adhesive and a plurality of phosphors; wherein the second end of each of the supporting arms comprises a clamping portion which clamps the body of the LED filament and the inner shape of the clamping portion is fitted with the outer shape of the LED filament, such that the orientation of the cross-section of the LED filament is properly adjusted to face toward a predetermined direction; wherein the LED filament is flexible LED filament and is bent to form a three-dimensional shape in the bulb shell, such that the LED light bulb emits omnidirectional light; wherein points of the LED filament in an xyz coordinates are defined as X, Y, and Z and the three-dimensional shape satisfies a curve equation, an origin of the xyz coordinates is at the stem top, an x-y plane of the xyz coordinates passes through the stem top and is perpendicular to the height direction, a z-axis of the xyz coordinates is coaxial with the stem, and the two conductive electrodes are disposed at two sides of a y-axis of the xyz coordinates, the curve equation is: X = m 1 * cos t * 360, where m1 is 24 < m1 < 27mm, Y = m 2 * sin t * 360, where m2 is 24 < m2 < 27mm, Z = n * cos t * 360 * k, where n is 0 < n ≤ 14mm, wherein, t is a variable between 0 and 1, the LED filament varies along an x-direction, a y-direction, and a z-direction according to t; wherein, when X=0, a max value of |Y| is m2, and a max value of |Z| is n; wherein, when Y = 0, a max value of |X| is m1, the max value of |Z| is n; wherein, when Z = 0, the max value of |X| is m1, and the max value of |Y| is m2; wherein, m1 is a length in the x-direction, m2 is a length in the y-direction, n is a height of the highest point from the x-y plane in the z-direction, and k is a number of the highest point (s) where k is an integer and 2 ≤ k ≤ 8. a bulb shell; a bulb base connected to the bulb shell; a stem disposed inside the bulb shell; at least two conductive supports (51a,51b) connected to the stem; an LED filament comprising a plurality of LED chips (102,104) and two conductive electrodes; and a plurality of supporting arms, each of the supporting arms comprising a first end connected to the stem and a second end connected to the LED filament; characterized in that each surface of the LED chips are covered by a top layer and a base layer, the top layer comprises an adhesive and a plurality of phosphors, the base layer comprises an adhesive and a plurality of phosphors; wherein the second end of each of the supporting arms comprises a clamping portion which clamps the body of the LED filament and the inner shape of the clamping portion is fitted with the outer shape of the LED filament, such that the orientation of the cross-section of the LED filament is properly adjusted to face toward a predetermined direction; wherein the LED filament is flexible LED filament and is bent to form a three-dimensional shape in the bulb shell, such that the LED light bulb emits omnidirectional light; wherein points of the LED filament in an xyz coordinates are defined as X, Y, and Z and the three-dimensional shape satisfies a curve equation, an origin of the xyz coordinates is at the stem top, an x-y plane of the xyz coordinates passes through the stem top and is perpendicular to the height direction, a z-axis of the xyz coordinates is coaxial with the stem, and the two conductive electrodes are disposed at two sides of a y-axis of the xyz coordinates, the curve equation is: X = m 1 * cos t * 360, where m1 is 24 < m1 < 27mm, Y = m 2 * sin t * 360, where m2 is 24 < m2 < 27mm, Z = n * cos t * 360 * k, where n is 0 < n ≤ 14mm, wherein, t is a variable between 0 and 1, the LED filament varies along an x-direction, a y-direction, and a z-direction according to t; wherein, when X=0, a max value of |Y| is m2, and a max value of |Z| is n; wherein, when Y = 0, a max value of |X| is m1, the max value of |Z| is n; wherein, when Z = 0, the max value of |X| is m1, and the max value of |Y| is m2; wherein, m1 is a length in the x-direction, m2 is a length in the y-direction, n is a height of the highest point from the x-y plane in the z-direction, and k is a number of the highest point (s) where k is an integer and 2 ≤ k ≤ 8.