Xishi bears are about 12-20 cm in length and 90-140 grams in weight. Males and females are slightly different. Generally, females are slightly larger and heavier. The average lifespan of Shih Tzu bears is 2 to 3 years.

Xi Tzu bears can mate and give birth throughout the year. The average gestation period is 15~17 days. Generally more than 4, up to 17. Shih Tzu bears are only about 2 grams when they are born, and they are sexually mature in about 7 weeks and can mate. Their body temperature is around 37-39 degrees, and with their long fur, they will feel hot and sensual in the hands.