Coronal mass ejections (CMEs) are the most spectacular phenomena of solar activities, and the solar events with the largest spatial scale. CMEs are often accompanied with other solar activities. Many solar phenomena are believed to have direct or indirect correlations with CMEs, such as solar flares, prominence eruption, helmet streamers, high-speed solar winds, coronal and interplanetary shock waves, and so on. Radio observations are an important complementary tool to study CMEs. Multi-frequency radio measurements not only study the initiation of CMEs, but also get more information on triggering mechanism of CMEs. In the present paper, we summarize the relationships between CMEs and low frequency radio bursts with the observational instruments and the radio signatures of CMEs being introduced and analyzed. The initiation mechanism and some open questions are discussed as well. Finally we claim that studies of CMEs must base on the multi-species data in all electromagnetic radiation wavelengthes.