Abstract : Abstract—Introduction The chemotherapy will decrease the cellular immunity in nasopharyngeal carcinoma patient. The decrease of cellular immunity caused increasing infection event. Infection event in nasopharyngeal carcinoma inhibit the next cycle chemotherapy so the chemotherapy result become poorly. This study aimed to collect the data about cellular immunity post 3 cycle neoadjuvant chemotherapy, infection frequently and the difference decrease cellular immunity between infection group and non-infection group in advance nasopharyngeal carcinoma undergoing 3 cycle neoadjuvant chemotherapy. Methods: This research use before and after observasional eksperimental, 1 group without control in 8th floor building A RSUPN Dr. Cipto Mangunkusumo (RSCM), July – September 2015. Analyzed by bivariat by T or Mann Whitney Test. Results: There are decline cellular immunity, CD 4+ (p=0,002), CD 8+ (p=0,001). Ratio CD 4+/CD 8+ in normal. 4 subject (29,4%) undergoing pneumonia, 1 subject (5,8%) undergoing oral mucositis and pneumonia. Non infection groups CD 4+ quantity are: 524,22; 408,11; 374,78; 296,78. Infection groups CD 8+ quantity are: 361,00; 280,00; 286,00; 218,00. Infection groups CD 8+ quantity are: 225,50; 361,00; 183,50; 168,00. Conclusion: The cellular immunity are decreased after 3 cycle neoadjuvant chemotherapy. Oral Mucositis and pneumonia are most frequently infection. There are a difference decrease cellular immunity between infection group and non-infection groups.