Tonal pitch in Standard Chinese is largely affected by so many factors like intonations, neighbour tones and speakers` intentions and so on. This paper aims to analyze pitch variation of Standard Chinese by means of normalized pitch slopes. Tonal pitch variation has so far been mainly studied through analyzing the pitch variation itself, but this paper shows that the variation is more conveniently analyzed with normalized pitch slope which is figured out by target pitch difference divided by target pitch duration after pitch- and time-normalizing of each data. Results of the analyses show that the tonal slope has following characteristics: The absolute value of tonal slope depends on the speaker`s intention in utterance. When the speaker`s intention is strong like a narrow focus in sentence, the absolute value of tonal slope is higher than a base slope. On the contrary, the absolute value becomes much lower, even happens to be changed into the opposite value of a base slope, when there are no informative words in utterance like an already-known information. This paper shows that the tonal slope in Standard Chinese is one of worth considering factors which can analyze the condition of tonal variation.