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Lower-band chorus waves are known to play dual roles in radiation belt dynamics (electron acceleration and precipitation), and understanding their properties and excitation is very important. A systematic study of chorus waves properties in terms of background plasma parameters (electron perpendicular beta β and the ratio of plasma frequency to electron cyclotron frequency f /f) has not been performed previously. We use burst mode data from Van Allen Probe A from 2014 to 2017 and develop an algorithm to extract individual lower band rising tone chorus elements. We statistically analyze four properties of rising tone chorus elements: time duration τ , frequency width ∆f , chirping rate Γ, and maximum intensity I. Statistical results show typical properties of chorus waves: I ∼ 0.09 nT, ∆f ∼0.08f , Γ ∼2 × 10 Hz/s, τ ∼ 0.015 − 0.25 s. On the nightside and dawnside, Γ shows wider spread and is more distributed over larger values, which is associated with the wider distribution of β. Chorus waves at duskside and dayside have larger values of τ , associated with smaller β and larger f /f. The dependence of chorus wave properties on background plasma parameters is also examined. We show that normalized ∆f has positive correlation with β and f /f. Normalized τ shows negative correlation with β and positive correlation with f /f , respectively. Normalized Γ shows positive correlation with β and negative correlation with f /f. These results help us better understand chorus waves excitation and their relation to the microburst.