Citrus longhorn beetle - Anoplophora chinensis (Forster), (CLB), which originated from PR of China, was firstly detected in nursery in Turanj, near Zadar, in 2007. Visual control of forest was performed in the area of great risk near ports Rijeka, Split and Zadar, as well as in parks, private gardens and nurseries that distribute planting material originating from the Far East. In the forest area there were 9 visual controls and no symptoms of infestation were found. 109 visual controls were performed in different areas of Croatia and collected were 128 samples with suspicious symptoms in which 112 larvae of citrus longhorn beetle - A. chinensis were found. On the Japanese maple - Acer palmatum Thumb. ex Murray 105 larvae were found and 7 on the rose - Rosa sp. potted plants that didn't originate from consignment imported from PR of China in 2007. Applied was new method of detection using trained hunting dogs and one larva was found, at the top of the stem of crape myrtle - Lagerstroemia indica L. in the year 2011. Larvae found in the period 2008 - 2011 were reared for the first time in the artificial diet. Also, larvae were placed in the holes of cut branches and potted plant of English oak - Quercus robur L.. These studies confirmed possibility of development of larvae into adult in the laboratory conditions. Maturation feeding proved that Japanese maple - Ac. palmatum Atropurpureum was the most suitable host followed by sycamore maple - Ac. pseudoplatanus and hazel - Corilus avellana L. Contorta. The most number of scars with laid eggs were on sycamore maple - Acer pseudoplatanus L. and it can be stated as the most suitable host for oviposition followed by hazel - C. avellana Contorta and London plane - Platanus acerifolia L. The smallest number of scars was on branches of sessile oak - Quercus petraea (Matt.) Liebl. and narrow-leafed ash - Fraxinus angustifolia Vahl. No scars were found on black locust - Robinia pseudoacacia L. Pest risk analyses (PRA) was performed and it showed that the biggest risk can cause planting material and bonsai plants from countries of great risk. Molecular analyses of larvae were performed by PCR-RFLP method in Vienna. Studies were performed and samples were analysed in the laboratory of Plant Protection Institute in Zagreb. Researches were performed in natural situation and laboratory.