Abstract: 【OBJECTIVE】In order to obtain the terraploid small-fruit-type tomato and study its characteristics. 【METHOD】Five tomato cultivars of Lycopersicum esculentum Mill.ssp.subspontaneum Brezh. were induced by 0.2% colchicine solution. We surveyed and researched the mutations of the plants by morphology and cytology methods and inducing effects of different tomato cultivars. 【RESULTS】Obvious changes have taken place on the mutant plants. In comparison with normal plants, mutant plants expressed the follow features: the growing of seedling is checked. The leaves appear to be darkish green and become thicker than that of diploid. The leaf shape index becomes smaller. The flowers became larger. The stomatal cell is larger and stomatal frenquency is reduced. The number of chloroplast in stomata is increased. The diameter of pollen became larger and the pollen viability is decreased. We noticed many forms of homologous chromosomes synapsis in meiosis of tetraploid tomato.【CONCLUSION】The results indicated that we obtained tetraploid plants of five small-fruit-type tomato cultivars with different inducement rate