THE just-concluded Seventh Guangdong Communist Party Congress has marked the beginning of a new era in the politics of China's most dynamic province. In addition to presenting a bold economic blueprint for the province in the coming decade, Guangdong Communist Party Secretary Mr Xie Fei has firmly established himself as the spokesman of this vanguard province and finally emerged from the shadow of hismentor, former governor Mr Ye Xuanping. Mr Ye, whose father was the late revolutionary general Ye Jingying, was once regarded as the ''godfather'' of the prosperous province and commanded great respect. According to sources, Mr Ye now spends much of his time in Beijing, having succeeded party elder Mr Wang Renzhong as the Executive Vice-Chairman of the Chinese People's Political Consultative Conference a year ago. Speaking at the end of the congress, Mr Xie - aided by his right-hand man, Guangdong Governor Mr Zhu Senlin - clearly conveyed the message that he was ''in charge'' when he was repeatedly challenged on questions ranging from political reform to Guangdong-Hongkong relations. The ''Xie signature'' was also evident in the composition of the new Standing Committee. Although only four of the 11 Standing Committee members are newcomers, at least three directly owe their promotion to Mr Xie, who is now a Politburo member of the Chinese Communist Party. They are Agriculture Vice-Governor Mr Au Guangyuan, Provincial Government Secretary-General Mr Huang Huahua and Guangdong police chief Mr Chen Shaoji - all in their early or mid-40s. The only surprise was 47-year-old Vice-Governor Mr Zhang Gaoli. Mr Zhang was chosen by Mr Ye in 1985 to head the provincial economic committee and was later put in charge of the province's infrastructure and industrial development. However, he was sidelined soon after Mr Zhu took over. According to sources, Mr Xie originally favoured propaganda chief Mr Yu Youjun joining the Standing Committee instead of Mr Zhang. But Mr Yu, the youngest candidate to stand for the election, was edged out by Mr Zhang and failed to make it to the powerful body. In fact, sources said the original arrangement was to include Mr Zhang only as a ''second choice'' for the election. But, mainly due to his age and lack of experience, Mr Yu was voted out in the final election. Nevertheless, sources said Mr Xie still managed to include a large number of his government cronies in the new party line-up that will essentially boost his control over the administration. The line-up included two ''trouble-shooters'' - Government Secretary-General Mr Huang and police chief Mr Chen - and at least two powerful vice-governors who have worked under the ''Xie-Zhu axis''. They are Executive Vice-Governor Mr Lu Ruihua and Mr Au.