Bicycle is a common and convenient traffic tools in China. A lot of people make use of it go to work or go for an outing. The great majority of students ride bicycle to go to school in china. People can ride a bicycle freely in side pavement. It is safe. Riding bicycles can relieve the pressure of traffic and reduce the air pollution and sound pollution. The buses, motors and cars let out a lot of tail gas which lead to the city air getting worse and worse. There are more and more people making use of the bicycle to lose weight and take exercise. Bicycles become more and more popular with young. Take America for example, there are 20 thounsand hundred persons riding bicycle, and the number of taking part in is increasing. Government encourages bicycles taking the place of cars. Bicycle is used as amusement and exercise equipment in America. The American drive the car to go to work. Now most of the Americans leave the cars at home, they make use of bicycle to go to work. The main reasons are the high price of gasoline, economic recession and environment protection. If you are a beginner, you can learn and practice slowly. It is necessary to choose a nice-looking bicycle which you favors. It should ride comfortably and the height of saddle should be adjusted suitably. The next step is that you should find a wide and open area to practice. When you sit on the saddle, your eyes should look at the front. Hands should not hold too tight. Don’t be too nervous. The most important thing of riding a bicycle is keeping balance. After weeks you can grasp how to ride. You may be afraid of falling over, but you can master freely. You can ride a bicycle to go shopping. Riding a bicycle keeps a joyful and optimistic mood, forgetting of the unhappy things. The people often ride bicycle keep full energy and enthusiasm. The people often ride bicycle can protect themselves and obey the traffic rules. The people often ride bicycle must be more careful and patient. They have perseverance to accomplish the task and overcome the troubles. They must become a responsible person. Riding a bicycle have the good effect to the body. Due to riding a bicycle is a periodic aerobic exercise, it can consume much calorie and energy. It can receive remarkable result of losing weight. Riding a bicycle will improve lung-heart function. It exercises the strengthen of the leg muscle and the whole body endurance. The modern medical science study demonstrates that it can prevent cerebrum degradation because it is an exercise of left and right foot treading alternately. It can exploit our left and right cerebrum at the same time. It improves the agility of nervous system. At the beginning of riding,you may feel tired of your muscle. The phenomenon will disappear after a time. In the summer you should pay attention to prevent from sunlight. You can rub some sunscreen cream, drink more water, and dress on the light clothes. Bicycle can relieve the burden of traffic. The noises in the city come from the horns of vehicle. The tail gas pollute the atmosphere and it is bad for health. It has become a problem of heat island effect in the city. The temperature in the city has being risen. Human-being is short of petroleum and the price of it is going up. Government should encourage riding bicycles.