For many of his patients, treatment comes with a full dose of education about TCM, which holds that the human body is inseparable from the rest of nature.
"Every part of the body, including the mind, is connected together," Xu said recently. "For example, if a patient has back pain, sore knees and ringing in the ears, he might be advised to see an orthopedist, a neurologist and an ear doctor by his American physician. A traditional Chinese doctor, however, would deem all that as symptoms of a single disease."
TCM practitioners do not treat single symptoms the way practitioners of Western medicine do, say by prescribing aspirin for a headache. Instead, they treat a pattern of symptoms, which they call symptom complexes, to rebalance the body and enable it to cure itself.
Most of Xu's clients are non-Asian. In fact, every Wednesday morning, he performs acupuncture with Leon J. Weiner, a medical doctor, in Weiner's clinic in the Northeast. Xu helps Weiner treat patients suffering from the stiffness and aches that result from Parkinson's disease or strokes.
"He is not a weekend student," Weiner said. "He learned from his family. There is certainly knowledge about the acupoints passed on secretly within the family. That's why he is better than many other acupuncturists."
Xu's preference for TCM does not exclude the need for Western medicine. He frequently refers patients to mainstream physicians, such as for heart conditions.
Most of Xu's time is spent at the 350-square-foot Arch Street center. The outer room is a pharmacy, where herbs in glass containers labeled in Chinese and Latin are aligned in cabinets. Two other rooms are used for consultation and treatment.
Ed Skinner said that immediately after Xu pushed needles into certain points of his body and let them stay there about 40 minutes, he felt "much relieved" and walked more easily.
"After several more treatments," Skinner said, "I could walk without a stick for a short distance and with only one for a longer distance. The needles killed the pain, too."
"The theory of TCM," Xu explained, "is based on the concepts of energy, named qi in Chinese, and change, that is, the yin-yang theory. If qi is not excessive or deficient in any part of the body, a person is well. Disease is the result of unbalanced qi."
Since qi flows through channels and meridians that form a two-way communication system between the organs and the surface of the body, Xu said, acupuncture involves stimulating specific points to influence the energy flow.
Xu also uses a treatment popular in today's China: introducing a small electric current into the needles to stimulate the acupoints. It has proven effective in treating pain, he said.
Then there are the herbs.
For 29 years, Brian Carney, 38, of Philadelphia, suffered from seborrhea, a chronic skin disease.
"My doctor said he had tried his best and told me to go back and rest," Carney said.
In 1992, a friend suggested that he visit Xu.
"Xu applied smashed herbs on my body and administered me several bags of herbs," Carney recalled. "I cooked the herbs with water and drank the soup three times a day. Two months later, the rash disappeared."
Herbal therapy, Xu said, does not aim to kill bacteria, viruses, cells and so forth but to rebalance the body so that it can heal itself. A formula is custom-designed for each patient according to his or her age, weight and medical condition.
Xu's family has practiced TCM in China for more than a century. His great- great-grandfather was a medical practitioner, but Xu knows little else about him. His great-grandfather was a doctor for the imperial family late in the Qing Dynasty (1644-1911). When the dynasty ended, the family moved to the county of Lin Yuan in Liaoning Province.
There, the family ran the area's largest medicine factory, pharmacy and clinic, manufacturing pills from powdered herbs and treating patients.
Xu learned TCM from his father, Guotai Xu, who became well known in Lin Yuan for his ability to cure digestive problems.
While still in high school, the young Xu memorized the names, functions and application of 400 herbs and the ingredients of 200 formulas. Later, he underwent four years of training at the Jian Chang Medical School in Liaoning before getting his bachelor's degree and one year's education in Western medicine at another medical school.
After one year's experience as a TCM practitioner in China, Xu moved to the United States in 1986. In 1990, he passed examinations administered by the National Commission for the Certification of Acupuncturists and received his license from the Pennsylvania Department of State.
In 1991, he opened his center. He advertises in Chinese-language newspapers, but most of his patients learn of him through word of mouth. Some first encounter him at the massage classes he teaches at his center and at Triton Regional High School in Runnemede, N.J.
Some patients visit Xu after years of suffering from chronic diseases. Some come because they prefer natural medical treatments. Others find TCM less expensive than Western medicine: An appointment usually costs $40 to $50, and the herbs are relatively inexpensive.
Then there are those patients who are drawn to the center by Xu himself, by his obvious commitment and sense of caring.
Dedication, Xu said, is a tradition in his family, one that he intends to carry on.
"My father always stresses the importance of morality," he said. "He is extremely responsible for his patients."