A strain of CMV (CMV-T37) which was widely found and caused tomato mosaic in Guangdong province was used as on inoculum to infect the virus-free banana plants by mechanical juice inoculation and by aphid transmission artificially in the green-house as naturally by growing infected tomato or/and cucumber plants in the trial fields.The results of all experiments were positive with high percentage of infection and showed that the solanaceous and cucurbitous plants infected by CMV-T37 might serve as the primary and secondary sources of infection of the banana mosaic disease,besides the diseased banana plants (including sucker) itself in Guangdong Province.