As a student of sexual life in ancient China, van Gulik wrote Erotic Colour Prints of the Ming Period (1951) and Sexual Life in Ancient China (1961). He also raised gibbons at home and wrote The Gibbon in China, which came complete with a recording of gibbons 'cries at the end of the book.
高羅佩研究中國古代兩性生活，出版「秘戲圖考」（Erotic Colour Prints of theMing Period,1951）、「中國古代房內考」（Sexual Life in Ancient China, 1961）兩冊專書；他又在自家養猿，詳作生態紀錄，寫成「長臂猿考」（The Gibbon inchina），書後附有猿啼唱片。