CHINESE Prime Minister Li Peng has given Shenzhen a shot in the arm by endorsing its free-market reforms. The supportive statements of the senior cadre, who will officiate at the opening of the Daya Bay nuclear plant tomorrow, were partly responsible for the 5.74 per cent jump in the Shenzhen stock index yesterday. Mr Li arrived at the special economic zone early yesterday morning after a five-day inspection of neighbouring Zhuhai. Security was extremely tight with police armed with sub-machine guns and assault rifles stationed on every road junction, while others patrolled in unmarked pick-up trucks. Mr Li's motorcade had more than 30 motorcycle outriders and half a dozen station wagons with heavily armed escorts. Sources in Shenzhen said Mr Li, who has visited Shenzhen annually in the past few years, headed straight to the local bourse. ''Li heaped praise on the stock exchange as a vehicle for raising capital and restructuring the state enterprise system,'' an informed source said. ''The premier expressed confidence the Shenzhen economy could cross a new threshold once every few years.'' ''However, the premier also told bourse staff that progress of the 'stocks system' must match the pace of development in the entire country.'' The source said his brief remarks were interpreted by brokers and investors as a pat on the back for Shenzhen and the Guangdong coast in general. The Credit Lyonnais index for Shenzhen's A shares shot up 98.09 points yesterday to close at the 1,807.18 mark. During a previous visit to the Shenzhen bourse, the premier issued a stern warning against ''speculationary activities'' and insisted that the facility remained a ''socialist stock exchange''. After a 30-minute stay in the bourse, Mr Li and his entourage, which included the Party Secretary of Guangdong, Xie Fei, headed for the local state guesthouse. ''Li listened to reports about Shenzhen's economic development the whole afternoon,'' a local journalist said last night. It is understood the premier gave instructions to a few cadres who would shortly take over leadership positions in the economic zone. Local sources said Mr Li would today tour major infrastructure projects in Shenzhen, including the new airport and the proposed container ports. Shenzhen officials said Mr Li had shown ''great personal concern'' for the Daya Bay facility, having visited it 10 times. The pro-Chinese Hong Kong daily Wen Wei Po reported yesterday that during his tour of Zhuhai, Mr Li gave an optimistic assessment of the economic zone's performance. ''Zhuhai's economic construction is successful amidst the waves of the reform and open door policy,'' the premier said. ''It is worthy of nationwide application and emulation.'' Mr Li gave instructions on the expansion of infrastructure projects, specially quickening the pace of the development of the outlying Hengqin Island. The premier also endorsed Zhuhai's strategy to tightening border restrictions between the zone and the rest of Guangdong while relaxing customs and immigration procedures for Macau and Hong Kong residents entering the area. ''We must continue to do well the job of developing the special economic zones so as to set an example for the whole nation,'' Zhuhai sources quoted Mr Li as saying. Cadres in Shenzhen said yesterday at a time when hundreds of China's open cities had been granted ''preferential policies'' akin to those of the special economic zones, Mr Li's remarks in the two zones were a great cause for reassurance. As is the custom with the provincial tours of senior cadres, Mr Li's presence in Shenzhen or Zhuhai was not recorded by local papers or TV stations. When told that it was Mr Li who was in town, local residents expressed wishes he could use his authority for the benefit of the zone. One driver suggested that the premier take a good look at Shenzhen's roads. ''The city Government never thought the place would develop this quickly,'' he said. ''The cars and lorries are all over the place. It's a real mess.''