降价是人类语言中一个普遍的语音现象，但在具体语言中又存在特殊性。基于现有研究，本文探讨了疑问语气、焦点位置及其交互作用对普通话声调降价的影响。研究发现：（1）在疑问语气上，汉语是非疑问句削弱了降价效应，对降价的阴平音节有音高抬升作用。（2）在焦点上，音域压缩增加了降价效果，焦点与降价序列之间的相对距离与降价阴平音节的调值呈正相关。当焦点与降价序列重合时，降价现象并不会消失。（3）在交互作用上，当焦点位于降价序列之前时，两个句类的降价阴平音节的最大音高值会被疑问语气抬高，在窄焦点句中有所削弱。当焦点与降价序列重合时，影响降价阴平音节音高的主要因素会由低音音节变成焦点。位于句末的降价音节同时受到疑问语气和焦点的影响，且来自疑问语气的影响多于焦点。

Downstep is a common phonetic phenomenon in human language, yet it also exhibits specificity in each language. This paper discusses the effects of interrogative tone, focus position, and their interaction on downstep in Mandarin. The findings indicate: (1) In terms of interrogative tone, non-interrogative sentences weaken the effect of downstep, having an upward pitch shift on the high-pitched syllables. (2) In terms of Focus, pitch compression increases the downstep, and there is a positive correlation between the distance from the focus to the downstep syllables and their pitch height. When the focus coincides with the downstep syllables, the downstep does not disappear. (3) In terms of interaction,  the maximum pitch of the downstep syllables is raised by the interrogative tone, which is weakened in narrow focus sentences. When the focus coincides with the downstep syllables, the main factor affecting the high-pitched syllables shifts from low-pitched syllables to the focus. The high-pitched syllables positioned at the end of the sentence are influenced simultaneously by the interrogative tone and the focus, with the influence from the former being greater than the later.Downstep is a common phonetic phenomenon in human language, yet it also exhibits specificity in each language. This paper discusses the effects of interrogative tone, focus position, and their interaction on downstep in Mandarin. The findings indicate: (1) In terms of interrogative tone, non-interrogative sentences weaken the effect of downstep, having an upward pitch shift on the high-pitched syllables. (2) In terms of Focus, pitch compression increases the downstep, and there is a positive correlation between the distance from the focus to the downstep syllables and their pitch height. When the focus coincides with the downstep syllables, the downstep does not disappear. (3) In terms of interaction,  the maximum pitch of the downstep syllables is raised by the interrogative tone, which is weakened in narrow focus sentences. When the focus coincides with the downstep syllables, the main factor affecting the high-pitched syllables shifts from low-pitched syllables to the focus. The high-pitched syllables positioned at the end of the sentence are influenced simultaneously by the interrogative tone and the focus, with the influence from the former being greater than the later.